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STEELE'S NEW CHEMISTRY. 






FOURTEEN WEEKS 



CHEMISTRY 



EXCHANGED, 




J. DOjeMAN>STEELE, Ph.D., 

AUTHOR OF THE FOURTEEN- WEEKS SERIES IN NATURAL SCIENCE. 



:• ; » « 



©7 ght and glorious is that revelation 
Written all o^er this great world of ours. " 

Longfellow 



A S. BARNES & COMPANY, 

NEW YORK, CHICAGO and NEW ORLEANS. 



THE FOURTEEN WEEKS' COURSES 

IN 

NATURAL SCIENCE, 

BY 

J. DORMAN STEELE, A.M., Ph.D. 

Fourteeij Weeks iij Natural Pljilosopfyy, 
Fourteei) Weeks iij CljenQistry j 
Fourteeij Weeks iij Descriptive Astroijonjy, 
Fourteeij Weeks iij Popular Geology, 
Fourteen Weeksjn Human Physiology, 
Foureeij Week [ iij Zoology, . 
Fourteeij Weeks irj Bohrjy, 

A Kjjy, containing Answers to the Questions 
ad Problems in Steele's 14 Weeks' Courses, 

\ PtSri^l series, 

ON THE "PLAN OF STEELE'S I4^WEEKS IN ! \ s HE SCIENCES. 

A Brief tyistor-y of the Uijited States, 
A Brief Fjistory of Fraijce, 



Tliti Fanfc^puDjishers dls& ©fferjthe following standard scientific 
wbrks, be1rf&*rh*>re extended of difficult treatises than those of 
Prof. Steele, though still of A endemic grade. 

< ' < i ' ee e r » 

,<' , ?eck's 'l.an§t'& Natural 'Philosophy, 

Porter's fcriijtnples of Cl^ftristry, 
Jar-vis' Pljysiologj and Laws of Healtlj, 
Wood's Botanist and Florist, 
djanjbers' Elenjents of Zoology, 
tyclijtyre's ^strorjomy and tlje Globes, 
Page's Elenjents of Geology, 



Entered according to Act of Congress, in the year 1873, by 

A. S. BARNES & CO., 

In the Clerk's Office of the District Court of the United States 

for the Southern District of New York. 

Steele's chkm. 

tJ S.Oeol Survey 
2?F'03 



r Rfi{ 



s*i 



TO THE FIRST EDITION. 

, _ 

IE" the preparation of tnis lii?^ ^oJinne the author lays 
no claim to originality: hk has been the far humbler 
task of endesTwitfg t# express, in simple, interesting 
language, a few of the principles &ja3 practical applica- 
tions of Chemistry. There is a larp'^ class of pupils in 
our schools who can piirste this bxanch only a single 
term, the time assigned to it in most institutions. They 
do not intend to become chemists, nor eyen professional 
students. If they wander through Q large text-book, they 
become confused by the multiplicity of strange terms, 
which they cannot tarry to master, and, as the result, too 
often only " see men as trees walking/' Attempts haye 
been made to reach this class by omitting or disguising 
the nomenclature ; but this robs the science of its mathe- 
matical beauty and discipline, while it does not fit the 
student to read other chemical works or to understand 
their formulae. The author has tried to meet this want 
by omitting that which is perfectly obyious to the eye — 
that which everybody knows already — that which could 



Viii PREFACE TO THE FIRST EDITION. 

not be long retained in the memory — and that which is 
essential only to the chemist. He has not attempted to 
write a reference-book, lest the untrained mind of the 
learner should become clogged and wearied with a multi- 
tude of detail. He has sought to make a pleasant study 
which the pupil can master in a single term, so that all 
its truths may become to him " household words." Bot- 
any, Natural Philosophy, and Physiology arc ciftii^cl, 
since they are now pursued as separate branches. Un- 
usual importance is giyen to that practical part of chemi- 
cal knowledge which concerns our eyery-day life, in the 
hope of bringing the school-room, the kitchen, the farm, 
and the shop in closer relationship. This work is de- 
signed for the instruction of youth, vxA. far their sake 
clearness and simplicity have been preferred to recondite 
accuracy. If to some young man or woman it becomes 
the opening door to the grander temple of Nature be- 
yond, the author will be abundantly repaid for all his 
toil. 

Notice. — The publication of " Fourteen Weeks in 
Chemistry," with the Old Nomenclature, is still con- 
tinued. Copies may be obtained of all booksellers, or 
of the publishers, A. S. Barnes & Co., New York and 
Chicago. 



PREFACE 

I 
TO THE REVISED EDITION. 



SIX years ago, at the solicitation of his fellow* 
teachers, the author offered this work to the pro- 
fession. Having been prepared for the use of his own 
classes, and embodying his oral instructions, it naturally 
partook of the peculiarities of that method. The desire 
was to interest pupils in scientific study. He be- 
lieved that a chemical fact is no less a truth because 
made attractive by an imaginative garb. If thus a child 
could be won to its consideration, the intrinsic beauty of 
the subject would lure him on, and so at last he would 
come to pursue it into the labyrinths of dry, technical 
works. 

The hearty reception of the book at once and its con- 
stantly increasing sale, the demand for an entire series 
on the same plan, words of approval from educators 
whose commendation it was a great satisfaction to have 
won, the fact that several other series based upon the 
same general idea have since appeared, and, above all, 
the assurance that the books have gone into hundreds 



X PREFACE TO THE REVISED EDITION. 

of schools where science had never been taught before — 
have convinced the author of the inherent correctness 
of his view. 

A demand having arisen for the admission of the new 
nomenclature into the book, the opportunity is gladly 
taken of making such revision as the daily use of the 
work in the class-room, and the advice of others, have 
suggested. 

The author would here acknowledge his special in- 
debtedness to the many teachers who, sympathizing with 
his plan of popularizing science, have pointed out what 
they considered defects in its execution, and given him 
the benefit of such illustrations and methods as they have 
found serviceable. The value of these criticisms has 
been shown in the increased worth of each edition of this 
series. 

The usual authorities have been freely consulted in 
this revision. The following have been found of es- 
pecial service : Miller's Elements of Chemistry (4th 
London Edition), Tomlinson's Miller's Inorganic Chem- 
istry, Eoscoe's Lessons in Chemistry (London, 1869), 
Bloxam's Metals, and Fownes's Manual of Chemistry 
(London, 1873). In addition, reference has been had to 
the works of Cooke, Draper, Nichols, Fresenius, Mus- 
pratt, Faraday, Watts, Stockhart, Moffit, Gmelin, Griffin, 
Tyndall, Odling, Noad, Williamson, Wilson, Galloway, 
Youmans, Eegnault, Thomson, Valetin, Gregory, Porter, 
Will, and many others. 



SUGGESTIONS TO TEACHERS. 



IT is advised that in the use of this book the topical 
method of recitation should be adopted. So far as 
possible, the order of the subjects is uniform — viz., Source, 
Preparation, Properties, Uses, and Compounds. The 
subject of each paragraph indicates a question which should 
draw from the pupil the substance of what follows. At each 
recitation the scholar should be prepared to explain any 
point passed over during the term, on the mention of its title 
by the teacher. Such reviews are of incalculable value. 
While some are reciting, let others write upon specified 
topics at the blackboard, after which the class may criticise 
the thought, the language, the spelling, and the punctua- 
tion. Never allow a pupil to recite a lesson, or answer a 
question, except it be a mere definition, in the language of 
the book. The text is designed to interest and instruct the 
pupil ; the recitation should afford him an opportunity of 
expressing what he has learned, in his own style and words. 
Every pupil should keep a lecture-book, in which to record 
under each general head of the text-book all the experi- 
ments, descriptions, and general information given by the 
teacher in class. In order to accustom the scholar to the 
nomenclature, use the symbols constantly from the begin- 
ning : they may seem dull at first, but if every compound 
be thus named, a familiarity with chemical language will be 
induced that will be as pleasing as it will be profitable. If 
time will admit, in addition, have weekly essays prepared 
by the class, combining information from every attainable 
source. 



Xll SUGGESTIONS TO TEACHERS. 

Ocular demonstration is absolutely necessary to any 
progress in the study of chemistry. Simple directions with 
regard to the experiments are given in the Appendix (see 
page 245) which will enable the unprofessional chemist to 
perform them readily, and, in case it is convenient for the 
pupils to work in the laboratory, will guide them in their 
investigations. The subject of Qualitative Analysis is also 
explained so clearly, and the directions are so complete 
(see page 268), that even the amateur student can grasp the 
subject and demonstrate its principles. 

Teachers desiring pleasant information to relieve the 
recitation hour, will find it in that delightful work of Dr. 
Nichols, Fireside Science. Many curious and entertaining 
stories and facts are given in a book entitled Treasures of 
the Earth. For a common work of reference, Miller's Ele- 
ments of Chemistry, 3 vols, octavo, will be most generally 
useful. These books may be obtained of the publishers of 
this series. 



TABLE OF CONTENTS. 



I. — I NTRODUCTION. 

PAGB 

DEFINITIONS 17 

NOMENCLATURE 19 

ATOMIC THEORY 21 

ACIDS, BASES, AND SALTS 22 

MATHEMATICS OF CHEMISTRY 24 



II.— INORGANIC CHEMISTRY. 

1.— THE NON-METALLIC ELEMENTS. 

Oxygen, Ozone and Antozone 27 

Nitrogen, Nitric Acid, Nitrous Oxide, etc 41 

Hydrogen, Water, etc 50 

Carbon, Carbonic Acid, Coal-Gas, Combustion, the Atmos- 
phere, etc 64 

Chlorine, Hydrochloric Acid, etc 102 

Iodine 107 

Bromine 106 

Fluorine 106 

Boron 108 

Silicon, Glass, etc 109 

Sulphur, Sulphuric Acid, etc 113 

Phosphorus, Matches, etc 119 

Arsenic 123 

2.— THE METALS. 

Potassium 126 

Sodium, Common Salt, etc 130 

Ammonium 134 

Calcium 136 

Strontium and Barium 140 



XVI TABLE OF CONTENTS. 

THE METALS— Continued. PAGB 

Magnesium 141 

Aluminum, Clay 143 

Iron 148 

Zinc 156 

Tin 157 

Copper 158 

Lead 159 

Gold 162 

Silver, Photography, etc 164 

Platinum 169 

Mercury, Mirrors, etc 170 

The Alloys 172 

III. — ORGANIC CHEMISTRY. 

INTRODUCTION 181 

Starch, Woody Fibre, and Sugar 184 

Fermentation, Beer, Wine, Vinegar, Alcohol, etc 192 

Organic Radicals 200 

Destructive Distillation, Petroleum, etc 204 

Organic Acids 210 

Organic Bases 212 

Organic Coloring Principles 216 

The Oils and Fats 218 

Resins and Balsams 225 

Albuminous Bodies 228 

Domestic Chemistry 232 

CONCLUSION, Chemistry of the Sunbeam, Circulation of 

Matter 237 

I V. — A P P E N D I X. 

1. The Names of Chemicals according to the Old and 

the New Nomenclature 243 

2. Simple Directions concerning the Experiments 245 

3. Chemical Analysis 273 

4. Questions for Class Use - 290 

5. List of Apparatus and Chemicals 307 

6. Index 309 



3ntro6uctton. 



'* Dead mineral matter," as we commonly call it, is instinct 
with force. Each tiny atom is attracted here, repelled there, 
holds and is held as by bands of iron. No particle is left to 
itself, but, watched by the Eternal Eye and guided by the Eter- 
nal Hand, all obey immutable law. When Christ declared the 
very hairs of our head to be numbered, he intimated a chemical 
truth, which we can now know in full to be, that the very atoms 
of which each hair is composed are numbered by that same 
watchful Providence. 



THE 



ELEMENTS OF C^EI^ISTRY. 



INTRODUCTION. 

Chemistry treats of the composition of bodies and 
the specific properties* of matter. — Examples: water 
consists of two gases, hydrogen and oxygen; gold is 
yellow. 

Organic Chemist?y deals with those substances 
which have been produced by life. — Examples : flesh and 
wood. Inoi*ganic Chemistry is confined to those 
which have not been formed by life. — Examples : sand, 
glass, metals. 

ALn HJlement is a kind of matter which has never 
been separated into other substances. — Examples: gold, 
iron. Sixty-four elements are now known, f fifty-one of 
which are considered to be metals and thirteen non- 
metals. 

Chemicat Affinity is that force which causes the 
elements of matter to unite and form new compounds. 
It acts at distances so slight as to be insensible, and upon 
the most dissimilar substances : the more dissimilar, the 

* See the Introduction to Physics for definitions of these terms. 

t It is not probable that the list is complete, but we cannot suppose that any- 
very abundaDt element is yet to be found. Indeed, of those made known since 
1774 (the year of the discovery of O, CI, etc.), the majority are only chemical 
curiosities.— The division into metals and non-metals is an arbitrary one, and 
not clearly defined. (See note, p. 123.) 



18 ELEMENTS OF CHEMISTRY. 

stronger the union. — Example : a little potassium chlo- 
rate * and sulphur mixed in a mortar will not combine, 
but a slight pressure of the pestle will bring them within 
the range of attraction, when they will burn with a loud 
explosion. Nothing in the nature or appearance of an ele- 
ment indicates its chemical affinity, and it is only by trial 
that we can tell with what it will combine. This attraction 
is not a mere freak of nature, but a force imparted to 
matter by God himself for wise and beneficent purposes. 

Compotmds, in their properties, are in general very 
unlike their elements, f — Examples : yellow sulphur and 
white quicksilver form red yermilion ; inert charcoal, 
hydrogen, and nitrogen produce the deadly prussic acid ; 
solid charcoal and sulphur make a colorless liquid ; poi- 
sonous and offensive chlorine combines with the brilliant 
metal sodium to form common salt. 

JTeat and Zdght fayor chemical action, and fre- 
quently develop an affinity where it seemed to be wanting. 
The former especially, by its expansive force, tends to 
drive the elements of a compound without the range of 
old attractions and within that of new ones. — Examples : 
gun-cotton, when lying in the air, is apparently harm- 
less, but a spark of fire will produce a brilliant flash, and 
cause it to disappear as a gas : nitrate of silver in contact 
with organic matter turns black, by the action of the light. 

Solution also aids in chemical change, as it destroys 
cohesion and leaves the atoms free to unite. — Example : 
sodium carbonate J and tartaric acid mixed in a glass 

* " Chlorate of potash." 

t " The elements have no more likeness to the compounds which they form 
than the separate letters of the alphabet have to the words which may be made 
from them." — Miller. 

% " Carbonate of soda." 



INTRODUCTION. 19 

will not combine, but the addition of water will cause a 
violent effervescence. 

Nomenclative. — The elements which were known 
anciently retain their former names. Those discovered 
more recently are named from some peculiarity. — Exam- 
ples : chlorine, from its green color ; bromine, from its 
bad odor. The uniform termination um has been given 
to the lately found metals. — Examples: potassium, 
sodium. A similarity of ending in non-metallic elements 
indicates some analogy. — Examples : silicon, boron ; 
iodine, bromine. 

Symdots. — For the sake of brevity chemists use a 
kind of short-hand. The first letter of its English name 
is generally taken as the symbol of an element. When 
that would produce confusion, the Latin initial is sub- 
stituted, and in some cases a second letter added. — Ex- 
amples: carbon and chlorine both commence with C; 
so the latter takes CI for its symbol. Silver and silicon 
both begin with Si, hence the former assumes Ag, from 
its Latin name, Argentum. If more than one atom of an 
element be used in forming a molecule of a compound, 
this is shown by writing the number below the symbol. — 
Example: H 2 indicates that in a molecule of water 
there are two atoms of hydrogen and one of oxygen. 

The Atomic WeigJit of an element expresses the 
proportion by weight in which it unites with other ele- 
ments. There is no chance-work in nature. No matter 
under what circumstances a compound is formed, the 
proportion of its elements is the same. — Example : the 
carbonic acid produced amid the roar of a conflagration 
or the explosion of a volcano is identical with that made 
in the quiet burning of a match. 



20 ELEMENTS OF CHEMISTRY. 

In the table on page 288 are given the symbols of the 
elements, their atomic weights, etc. The metals are 
printed in Eoman letters and the non-metals in italics. 
Hydrogen is taken as the unit of atomic weight. 

Constitution of Bodies.* — All bodies are con- 
sidered to be collections of molecules, as molecules f are 
of atoms. In some of the elementary substances the 
molecule and the atom are identical, but in many kinds of 
matter several atoms are combined to form a molecule. 
Thus the molecules of nitrogen, chlorine, and oxygen, 
contain two atoms each, and arsenic and barium four. J 
The molecule of a compound always contains two or 
more atoms. The molecule is destructible, but the atom 
is indestructible. The specific properties of a substance 
reside in the molecule, and to break up the molecule is to 
destroy the substance. A physical change goes no further 
than the molecule, and hence does not affect the integrity 
of a substance; but a chemical change consists in are- 
arrangement of the atoms and the formation of new 
molecules, and hence, of new properties. Whenever a 
combination then takes place it is by elementary atoms 
and not by molecules. In Physics we learned how physi- 
cal changes are caused by transformations of force with- 
out loss of energy. In Chemistry we shall see how 
chemical changes are produced by transformations of 
atoms without loss of matter. 



* The subject of the quantivalence of atoms is treated on page 142, as some 
knowledge of the chemical behavior of atoms is necessary fully to understand its 
force. 

+ A molecule is the smallest particle of a substance which can exist in a sepa- 
rate form. It is the unit of the philosopher as the atom is of the chemist, 

X See the table in Appendix, page 288, under Molecular Weight. 



INTRODUCTION. 21 

The Atomic Theory which lies at the basis of 
chemistry, as now understood, supposes: 

1. That each element is composed of indivisible* atoms 
which are exactly equal in size and weight. 

2. That the atomic weights represent the relative 
weights of the atoms of various kinds. 

3. That compounds are formed by the union of atoms of 
different kinds in the proportion of their atomic weights 
or multiples of them. 

4. That the molecular weight of a compound is equal 
to the sum of the atomic weights of its elements. 

A jBina?y Compound is a union of two elements. 
In writing its symbol, we place first that of the electro- 
positive,! and then that of the electro-negative element. 
In writing the name, or in reading the symbol, the latter 
element takes the termination ids. Thus potassium and 
iodine form the compound which is written KI, and read 
potassium iodide ; sodium and chlorine, NaCl, sodium 
chloride; zinc and oxygen, ZnO, zinc oxide. J 

One atom of in a molecule forms the monoxide or 
protoxide, two the dioxide or binoxide, three of and 
two of the other element, the sesquioxide (meaning 1-J-), 
and the highest number, the peroxide. Thus, 

* The atoms are termed indivisible, as the chemist cannot break up an atom 
of O any more than the astronomer can the planet Jupiter. Yet there is no 
more reason for supposing the elementary atom incapable of division by pro- 
cesses now unknown than that Jupiter cannot be resolved into smaller masses. 

t See these terms denned under Electricity in Fourteen Weeks in Physics. 

X There are three variations from this statement which should be noticed. 
1. Many chemists give the electro-positive element the termination ic, thus read- 
ing KT, potassic iodide. 2. The electro-negative element is often read first, 
and the word of placed between the elements ; thus KI is called the iodide of 
potassium. 3. In the case of phosphorus, carbon, and sulphur, the termination 
uret is sometimes used instead of ide ; thus FeS is read the sulphuret of iron, 
instead of iron (ferrous) sulphide or the sulphide of iron. 



22 ELEMENTS OF CHEMISTRY. 

N 2 = Nitrogen Monoxide (protoxide), 
N 2 2 = " Dioxide (binoxide), 

N 2 3 = " Trioxide, 
N 2 4 = " Tetroxide, 

N 2 5 = M Pentoxide. 

Acids, !Bases, and Salts. — There are two large 
classes of oxides chemically opposed to each other, termed 
acids and bases ; their compounds are called salts. 

The Acids are generally sour * and turn vegetable 
colors — such as the infusion of blue litmus, or of purple 
cabbage f — to a bright red. They are named from the 
elements with which combines. The termination indi- 
cates the amount of 0, — ic representing the greater, and 
ous the lesser. — Example: sulphur forms two acids of 
different strength — sulphuric, the stronger, and sulphur- 
ous, the weaker. If an acid has been afterwards found 
containing more than the stronger, it takes the prefix 
per ; one having less than the weaker, the prefix hypo. — 
Example : chlorine combines with oxygen and hydrogen 
to form a series of acids in regular gradation. 

Hypochlorous Acid HC10, 

Chlorous " HC10 2 , 

Chloric " HC10 3 , 

Perchloric " HC10 4 . 

Hydrogen by its union with different elements forms 
acids which contain no 0. These combine the names of 

* Certain acids, as well as certain bases, are insoluble in water, and hence 
have no taste. They, however, combine to form salts, which is their true test. 

t Paper tinged blue with a solution of litmus (a coloring matter obtained from 
certain lichens) should be constantly at hand in the laboratory, to determine the 
presence of a free acid. The same paper faintly reddened by vinegar, or any 
other acid, is a convenient test for the alkalies. The cabbage solution is made 
by steeping red cabbage-leaves in water, and straining the purplish liquid thus 
obtained. 



INTRODUCTION. 28 

both elements. — Example: hydrogen and chlorine form 
hydrochloric acid. 

The Sases are commonly oxides of the metals. Their 
termination, as in the acids, indicates the amount of oxy- 
gen. Thus mercury has two oxides, HgO and Hg 2 0, 
termed respectively mercuric oxide and mercurous oxide; 
iron forms FeO, ferrous, and Fe 2 3 , ferric oxide. The 
alkalies* are bases which are soluble in water, have a 
soapy taste and feel, turn red litmus to blue, and red- 
cabbage solution to green, neutralize the acids and re- 
store the colors changed by them. The property ivhich 
the acids and bases thus have of uniting with each other 
and destroying the chemical activity ivhich either possesses 
alone, is their distinguishing trait, f 

The Sails are compounds formed by the union of an 
acid and a base. J In naming a salt, the termination of 
the acid is changed — an ic acid forming an ate compound, 
and an ous acid an ite compound. Thus the salts of sul- 
phuric acid are called sulphates, and of sulphurous acid, 
sulphites ; of nitric acid, nitrates, and of nitrous acid, ni- 
trites. Sulphuric acid combining with ferrous oxide forms 
ferrous sulphate, and with ferric oxide, ferric sulphate. 

A formula is an algebraic statement of the sym- 
bols and relations of several compounds. The sign + in- 

* The alkalies are compounds of H, O and a metal. They are hence called hy- 
droxides : as KHO (potassium hydrate, caustic potash), NaHO (sodium hydrate). 

t To a part of the purple-cabbage solution add a few drops of a solution of 
caustic potash : a green liquid will be produced. To another portion add a few 
drops of sulphuric acid: the solution will become red. Pour the red acid liquor 
into the green alkaline one, and stir the mixture : the red color at first disap- 
pears, and the whole remains green ; but on adding it cautiously, a point is 
reached at which it assumes a clear blue color. There is then no excess of acid 
or alkali ; and on evaporation, a neutral salt, potassium sulphate, may be obtained. 

% We shall come hereafter to substitute for this simple definition the more 
exact chemical one, that a salt is an acid in which one or more atoms of H have 
been replaced by a metal. (See note, p. 44 - reaction, n. 51: and notes, p. 128.) 



&£ ELEMENTS OF CHEMISTRY. 

dicates a feeble attraction or a mere mixture. The sign 
= indicates conversion into. The comma or the period 
denotes a combination. The brackets and coefficients are 
used as in algebra. 

MatJiemalics of Chemistry. — There is a Divine 
law of harmony which runs like a golden thread through 
all nature, giving always unity and completeness. Its 
beauty and simplicity are nowhere seen more clearly 
than in the law of atomic weights. Applying the fourth 
principle of the atomic theory, we see that the atomic 
weight of any element in a compound, divided by the 
molecular weight of that compound, is the proportion of 
that element contained in it. — Example : the molecular 
weight of water, H 2 0, is 2 + 16 = 18; hence the propor- 
tion of H is T 2 H or ^, and of 0, yf or f . In 10 lbs. of 
H 2 0, there are therefore 10 xf or 8f lbs. of 0, and 
10x1 or lilbs. of H.* 

Apply this principle to the solution of the following 

PROBLEMS. 

1. In a 25-lb. sack of table salt (NaCl, sodium chloride), how many 
lbs. of the metal sodium ? f 

2. In 14 lbs. of iron-rust (Fe 2 O : 0, how much ? 

3. How much S is there in 2 lbs. of S0 2 ? 

4. How much S is there in 2 lbs. of H 2 S0 4 (sulphuric acid)? 

5. How much is there in 5 lbs. of HN0 3 (nitric acid)? 

6 How much H is there in 6 lbs. of HC1 (hydrochloric acid) ? 
7. How much potash (K 2 0) could be made from 3 lbs. of potas- 
sium (K)?J 

* This may also be solved by the following proportion :— 
The atomic weight of an element : molecular weight of a compound : : weight 
of the element : weight of the compound. 
2:18::iC: 10 lbs. a?=l| lbs. (H). 
16 : 18 : : X : 10 lbs. £=8§ lbs. (O). 
t 23 : 58.5 : : x : 25 lbs. x=9 r \\ lbs. (Na). 
t T8 : 94 : : 3 lbs. : x. a=3& lbs. (K a O). 



II. 

inorganic Chemistry 



" In the de-oxidation and re-oxidation of the hydrogen in a 
single drop of water, we have before us, so far as force is con- 
cerned, an epitome of the whole of life." — Hinton. 





1890 J 

INORGANIC CHEMISTRY, 



THE NON-METALS. 

OXYGEN. 

Symbol, Atomic Weight, 16 Specific Gravity, 1,1. 

The name Oxygen means acid-former, and was given 
because it was supposed to be the essential principle of 
all acids ; but hydrogen has since been found to be the 
true acid-maker. 

Fig. 2. 




Collecting O over a pneumatic tub. 



28 INORGANIC CHEMISTRY. 

Source. — is the most abundant of all the elements — 
comprising by weight \ of the air, f of the water, f of 
all animal bodies, and about \ of the crust of the earth. 

Preparation. — The simplest method of preparing for 
experimental purposes is to heat a mixture of potassium 
chlorate (KC10 3 ) and manganese dioxide (Mn0 2 )* in a 
flask, and collect the gas oyer a pneumatic tub, as in the 
accompanying illustration, f 

The ^Reaction, chemical change, is as follows : 



2 KC10 3 




2 KC1 + 

Two molecules of potassium chlorate are converted into 
two of potassium chloride and six atoms of 0, which pass 
off as a gas. The reaction may also be represented thus : 

(Potassium Chlorate) (Potassium Chloride) 

2 K CI O3 = 2K CI + 

2(39 + 35.5 + 3x16) 2(39 + 35.5) 




245 149 

'245 

The set free will be equal to -$fe of the potassium 
chlorate used, i. e., every 245 parts by weight (grs., oz., 
or lbs.) will yield 96 parts (grs., oz., or lbs.) of 0, and 
149 parts (grs., oz., or lbs) of KG. 

A Curious Fact appears in this process. If the 
KCIO3 were heated alone, a very high temperature would 

* This substance is commonly known as binoxide of manganese, and, because 
of its color, the black oxide of manganese, 
t See Appendix for directions in performing this and other experiments. 



0XYGE2T. 



29 



be necessary, which would liberate the gas rapidly, and 
often with explosive violence. If, however, we mix with 
it a little manganese dioxide, the gas will be set free at a 
much lower temperature, and may be regulated so as to 
come off a bubble at a time. At the conclusion of the 
process, the Mn0 2 will be found unchanged. The reason 
of this wonderful action is beyond our comprehension. 
The influence of one body over another, by its mere 
presence, is called catalysis. 

Properties. — has no odor, color, or taste. It com- 
bines with every element except fluorine. From some of 
its compounds it can be set free by the stroke of a ham- 
mer, while from others it can be liberated only by the 
most powerful means. Its union with a substance is 
called oxidation, and the product an oxide* It is a vigor- 
ous supporter of combustion. 

The following experiments will illustrate its chemical 
energy. 

1. By blowing quickly up- 
ward upon a candle, extinguish 
the flame, and leave a glowing 
wick. If this be plunged into 
a jar of 0, the coal will burst 
into a brilliant blaze. The 
experiment may be repeated 
many times before the will 
be exhausted. A new colorless a candle in o. 

gas, CO 2? called carbonic anhy- 
dride* (" carbonic acid") is formed by the combustion. 



Mg. s. 




* An anhydride (without hydrogen) is a substance which, when dissolved in H y O 
will unite with its elements and form an acid. It is then strictly a salt in which 
H plays the part of a base, and is called a hydride. In this state only is it 



INORGANIC CHEMISTRY. 




A watch-spring in O. 



2. Straighten a watch-spring 
by drawing it between the fin- 
gers. Pass one end through a 
cork, heat the other slightly 
and dip it into powdered sul- 
phur. Light this and plunge 
it into a jar of 0, holding it in 
the neck by the cork. The 
burning sulphur will ignite the 
steel, which will burn with a 
shower of fiery stars, while melted globules of the black 
oxide of iron (Fe 3 4 ) will fall upon the plate below. 

3. Ignite a bit of sulphur placed 
on a stand, and invert over it a 
jar of : it will burn with a beau- 
tiful blue light, and the fumes of 
sulphurous anhydride, S0 2 ("sul- 
phurous acid ") will circle about the 
receiver in curious concentric rings. 
The gas has a pungent odor, and 
will be absorbed by the water on 
the plate, where it may be tested. 
4. Place in the bottom of a " deflagrating spoon/' 
(see Appendix, p. 248) a little fine, dry chalk ; then wipe 
a bit of phosphorus, about the size of a pea, very care- 
fully and quickly between pieces of blotting-paper ; lay 
this upon the chalk, and, holding the spoon over a large 

properly termed an acid. The two compounds are frequently distinguished as 
anhydrous (without water), and hydrated (with water). Until of late it has 
been customary to apply the term acid to either form. Thus C0 2 (carbon di- 
oxide) is strictly carbonic anhydride, but has been so long known as carbonic 
acid that its proper appellation is rarely used. The same is true of the acids 
named in the 3d. and 4th. experiments. 




Sulphur in 0. 



OXYGEN. 
Fig. 6. 



SI 




Phosphorus in O. " The phosphoric sun." 

jar of 0, ignite the phosphorus with a heated wire, and 
lower it steadily into the gas. The phosphorus will 
burst into a flood of blinding light, while dense fumes of 
phosphoric anhydride, P 2 5 , ("phosphoric acid") will 
roll down the sides of the jar. 

5. Make a little tassel of zinc-foil, tip the ends with 
sulphur as in the 2d experiment, ignite and lower into a 
jar of 0. It will burn with a dazzling light, forming zinc 
oxide (ZnO). 

6. If a piece of charcoal-bark be ignited and lowered 
into a jar of 0, it will deflagrate with bright scintilla- 
tions. 

The "Destructive Agent of the Air. — is the 
active principle of the atmosphere. Comprising one-fifth 
of the common air, it is ever-present, and ever-waiting. 
We gather a basket of peaches and set them aside. In a 
short time, black spots appear, and we say they are decay- 



82 INORGANIC CHEMISTRY. 

ing. It is only the corroding them,, i. e., breaking up 
their chemical structure to form new and unpleasant 
compounds. To prevent this action, we place the fruit 
in a can, heat it to expel the 0, and seal it tightly. — We 
open the damper of the stove and the air rushes in. The 
immediately attacks the heated fuel. Every two atoms 
combine with an atom of C and fly off into the air as C0 2 . 
— We cut a finger, and soon feel the at work upon the 
quivering nerve beneath. We apply a strip of "court- 
plaster " to keep out the air and give nature an oppor- 
tunity to heal the wound.* — Our teeth decay only because 
of the action of the 0. The dentist saves them by filling 
any break in the enamel with a cement which is already 
oxidized, or with a metal, as Au or Pt, which has little 
affinity for 0. — The H 2 in the cistern becomes foul and 
putrid. We uncover it : in rushes the 0, picks up each 
atom of impurity, and sinks to the bottom. The thick 
sediment we find when it is cleaned in the spring, is but 
the ashes of this combustion, f — The blacksmith draws a 
red-hot iron from his forge. While the metal is glowing, 
the forms scales of the black oxide of iron (Fe 3 4 ), 
which fly blazing in every direction. J — We wipe our knives 



* The treatment of a burn as well as a cnt consists in the immediate exclusion 
of the air. It is a mistake to suppose that a salve will "draw out the fire 1 ' 
of a burn, or heal a bruise or cut. The vital force must unite the divided tissue 
by the deposit of material, and the formation of new cells. {Physiology, p. 205.) 

t "As the vessel sets sail from London, the captain fills the water-casks with 
water from the River Thames, foul with the sewage of the city, and containing 23 
different species of animalcules ; yet, in a few days, the O contained in the air 
dissolved by the H 2 0, will have cleansed it, and the H 2 will be found sweet 
and wholesome during the voyage." 

X Quite in contrast to this pyrotechnic display is the action of the O upon the 
Fe contained in writing-fluid. At first the words are pale and indistinct, but in 
a few hours the 0, noiselessly combining with the metal (see p. 212), brings out 
every letter in clear, bold characters upon the page. 



OXYGEN. S3 

and forks, and lay them carefully away ; but if we have 
left on them a particle of moisture, since H 2 favors 
chemical change, the will find it, and corrode the 
steel.* — An animal dies, and the at once begins to re- 
move the body. The atoms which have been used to 
perform the functions of life, are separated by the 0, and 
set at liberty to enter into new combinations. 

in tlie ITuman System.— We take the air into 
our lungs. Here the bloodf absorbs the 0, and bears it 
to all parts of the body, depositing it wherever it is 
needed. Laden with this life-giving element, the vital 
fluid sweeps tingling through every artery and vein, dis- 
tends each capillary tube, sends the quick flush to the 
cheek, combines with a portion of the food thrown into 
the circulation from the stomach, breaks up every worn- 
out tissue, burns up the muscles, and sets free their force, 
until at last it comes back through the veins dark and 
thick with the products of the combustion — the cinders 
of the fire within us. 

Combustion and Heat. — All ordinary processes 
of fermentation, decay, putrefaction, and fire, are pro- 
duced by a union of with a substance, and are 
only different forms of oxidation. They differ in the 
time employed in the operation. If unites rapidly, 



* The compound here formed will be a higher oxide than that produced at the 
blacksmith's forge, since a portion of the O which there united with the iron 
was driven off by the heat. It will be the red oxide of iron (Fe 2 O s , ferric oxide), 
or common iron rust, as we see it on stoves and other utensils. 

t The blood is full of red corpuscles or cells containing Fe. These are so tiny, 
that a million of them cluster in the drop which will cling to the point of a 
needle. Quickly assuming a tawny hue, like the decayed leaves of autumn, 
ihey change so rapidly that 20,000,000 perish with every breath.— Draper. 

These cells when fresh act like little gas-bags in carrying the O through the 
body. 



SJf INORGANIC CHEMISTRY. 

we call it fire; if slowly, decay. Yet the process 
and the products are the same. A stick of wood 
is burned in the stove, and another rots in the 
forest, but the chemical change is identical. In the 
combination of an atom of 0, a certain amount of heat 
is produced.* Hence, the house that decays in fifty 
years, gives out as much heat during that time as if 
it had been swept off by a* fierce conflagration in as 
many minutes. 

The Human Furnace . — The body is like a stove in 
which fuel is burned, and the chemical action is precisely 
like that in any other stove. This combustion produces 
heat, and our bodies are kept warm by the constant fire 
within us. We thus see why we fortify ourselves against 
a cold day by a full meal. When there is plenty of fuel 
in our human furnaces, the burns that ; but if there 
is a deficiency, the destructive must still unite with 
something, and so it combines with the flesh ; — first the 

* "When considerable masses of iron are allowed to rust, a distinct elevation 
of temperature is often perceived. This is seen when a heap of iron turnings 
of from 10 lbs. to 20 lbs. is moistened with water and exposed to the air. A 
curious illustration of the fact was afforded during the manufacture of the Medi- 
terranean Electric Cable. The copper conducting wire of this cable was coated 
with gutta-percha ; this was covered with a serving of tar and hemp, and the whole 
was enclosed in a strong casing of iron wire. The cable as it was manufactured 
was coiled in tanks filled with water. These tanks leaked, and the water was 
therefore drawn off, leaving a quantity of cable, about 163 nautical miles in length, 
coiled into a mass about 30 feet in diameter with an eye or central space of 6 
feet ; the height of the coil was about 8 feet. Kapid oxidation took place, and 
the temperature at the centre of the coil, nearly three feet from the bottom, rose 
in four days from 66° to 79°, although the temperature of the air did not exceed 66° 
during the period, and was as low as 59° part of the time. In other parts of the 
mass the heat rose so high as to cause the water to evaporate sufficiently rapidly 
to produce a visible cloud of vapor, and to give rise to apprehensions that the 
insulating power of the cable would be destroyed by the softening of the gutta- 
percha. No doubt the rise of temperature would have been still greater had it 
not been checked by the affusion of cold water ; but t?;e oxidation and the heat- 
ing were renewed when the cooling was discontinued. The oxidation occurred 
only on the external surface of the iron wires, that portion in contact with the 
tarred hemp remaining perfectly bright."— Miller. 



OXYGEN. 35 

fat, and the man grows poor ; then the muscles, and he 
grows weak ; finally the brain, and he becomes crazed. 
He has simply burned up, as a candle burns out to dark- 
ness. 

'Produces Motion. — As soon as we begin to per- 
form any unusual exercise, we commence breathing more 
rapidly, — showing that, in order to do the work, we need 
more to unite with the food * and muscles. In very vio- 
lent labor, as in running, we are compelled to open our 
mouths, and take deep inspirations of 0. This increased 
fire within elevates the temperature of the body, and 
we say " we are so warm that we pant." Keaily it is the 
reverse. The panting is the cause of our warmth. 

During sleep the organs of the body are mostly at rest, 
except the heart. To produce this small muscular exer- 
tion very little is required. As our respiration is, there- 
fore, slight, our pulse sinks, the heat of our body falls, 
and we need much additional clothing to keep warm.f 
Thus we require not only to keep us warm, but also to 
do all our work. Cut off its supply, and we grow cold ; 
the heart struggles spasmodically for an instant, but the 
motive power is gone, and we soon die. 

How gives us Strength . — Our muscles, as well 
as the food from which they are formed, consist of com- 

* It is probable that a portion of our food, especially the carbonaceous, is oxi- 
dized directly without becoming an integral part of the body. The heat thus set 
free by the principle of the correlation of force (see Physiology, page 134), may be 
converted into muscular force. 

t Animals that hibernate show the same truth. The marmot, for instance, in 
summer is warm-blooded ; in the winter its pulse sinks from 140 to 4, and its 
heat corresponds. The bear goes to his cave in the fall, fat ; in the spring he 
comes out lean and lank. Cold-blooded animals have very inferior breathing 
apparatus. A frog, for example, has to swallow air by mouthfuls, as we do 
water. Others have no lungs at all, and breathe in a little air through the skin, 
enough to barely exist. Is it strange they are cold-blooded ? 



86 INORGANIC CHEMISTRY. 

plex organic bodies, and the tension of the pent-up force 
is very great. Thus in flesh, starch, sugar, etc., the mol- 
ecules are yery large (see p. 100), and, when these oxidize 
into the smaller ones of water, carbonic acid, and am- 
monia, the hidden energy thus liberated gives us heat 
and strength.* It is merely the transference of force 
from one organic body to another. One decays, the other 
grows. One drops in the scale of life, the other rises. 
One loses as the other gains. As no matter is either lost 
or gained in any chemical change, so also no force is lost 
or gained, but all must be accounted for. Action and 
reaction are equal in chemistry as in philosophy. 

The Suming of the jBody by 0. — A man weigh- 
ing 150 lbs. has 64 lbs. of muscle. This will be burned 
in about 80 days of ordinary labor. As the heart works 
day and night, it burns out in about a month. So that 
we have a literal "new heart " every thirty days. We 
thus dissolve, melt away in time, and only the shadow of 
our bodies can be called our own. They are like the 
flame of a lamp, which appears for a long time the same, 
since it is " ceaselessly fed as it ceaselessly melts away." 
The rapidity of this change in our bodies is remarkable. 
Says Dr. Draper : " Let a man abstain from water and 
food for an hour, and the balance will prove he has 
become lighter." This action of O, so destructive — wast- 
ing us away constantly from birth to death, is yet essen- 
tial to our existence. Why is this ? Here is the glorious 
paradox of life. We live only as we die. The moment 
we cease dying, we cease living. All our life is produced 

* This latent force is called a potential one, and the same force, when sensible, 
is termed a dynamic one. In the former case it is hidden and ready to burst 
out at any time ; in the latter, it is in full action. Potential force is contained in 
the powder of a loaded gun. Dynamic force drives the bullet to the mark. 



OXYGEN. 87 

by the destruction of our bodies. No act can be per- 
formed except by the wearing away of a muscle. No 
thought can be evolved except at the expense of the 
brain. Hence the necessity for food to supply the con- 
stant waste of the system,* and for sleep to give nature 
time to repair the losses of the day. Thus, also, we see 
why we feel exhausted at night and refreshed in the 
morning. 

tfie Common Scavenger. — God has no idlers in 
his world. Each atom has its use. There is not an extra 
particle in the universe. The mission of oxygen, so de- 
structive in its action, is therefore essential, that every 
waste substance may be collected and returned to the 
common stock, for use in nature's laboratory. In per- 
forming this general task, its uses are most important 
and necessary. It sweetens water, it keeps the avenues 
of the body open and unclogged,f it preserves the air 
wholesome.. It becomes, in a word, the universal scaven- 
ger of nature. Every dark cellar of the city, every recess 
of the body, every nook and cranny of creation, finds it 
waiting ; and the instant an atom is exposed, the oxygen 
seizes upon it. A leaf falls, and the forthwith com- 
mences its destruction. A tiny twig, far out at the end 
of a limb, dies, and the immediately begins its removal. 
A pile of decaying vegetables, a heap of rubbish, the dead 
body of an animal, a fallen tree, the houses we build for 

* This food must be organic matter endowed with potential power treasured 
up in the plant. When it is transformed into flesh, perhaps made still more 
vital in the process, we have this force standing ready to be used again at our 
pleasure. When we will it, the O combines with the flesh and sets free the en- 
ergy for us to apply. 

t Huxley very prettily calls O, in this connection, the "great sweeper" of the 
body, since it lays hold of all the waste matter of the system, and burning it up, 
removes it out of the way. 



88 INORGANIC CHEMISTRY. 

our shelter, even the monuments erected above our final 
resting-place, are all gnawed upon by what we call the 
"insatiate tooth of time." It is only the constant corro- 
sion of this destructive agent — oxygen. 

Consumption of 0. — Each adult uses daily \\ lbs. 
of 0. The combustion of 1 lb. of coal requires 2§ lbs. 
of : so that the ship which burns 1,000 tons in crossing 
the ocean, takes out of the air 2,666 tons of 0. Suppos- 
ing the population of the earth to be 1,200,000,000, and 
each person to consume 1 lb. of O ; adding as much 
more to sustain fires; twice as much for the w T ants of 
animals, and four times as much for the varied processes 
of decay, the daily consumption of O reaches the enormous 
sum of 4,800,000 tons (Faraday). Yet the atmosphere 
contains over one quadrillion tons, and even this yast 
aggregate is a mere fraction compared with the O locked 
up in the ocean and the rock. 

^Results if the Air were Undiluted O.— The 
fire element would run riot everywhere. Metal lamps 
would burn with the oil they contain. Our stoves would 
blaze with a shower of sparks. A fire once kindled 
would spread with ungovernable velocity, and a uni- 
versal conflagration would quickly wrap the world in 
flame. 

OZONE. 

Ozone is an allotropic form of O — i. e., a form in which 
the element itself is so changed as to have new prop- 
erties. 

Source. — It is always perceived during the working of 
an electric machine, and is then called "the electric 



OZONE. 



39 



smell." It has also been detected near objects just struck 
by lightning. Electricity is supposed to have something 
to do with the formation of the ozone in the atmos- 
phere. 

Preparation . — Pour a lit- Fig. 7. 

tie ether into a jar of com- 
mon air, and stir in its 
vapor a heated glass rod. 
The will be immediately 
changed into its allotropic 
form — ozone — which can be 
recognized by its pungent 
odor. It may also be tested 
by a paper wet with a mix- 
ture of starch and potassium 

iodide ( KI). The OZOne Sets Preparing ozone. 

free the iodine, which unites 

with the starch, forming blue iodide of starch.* At a 
temperature a little above that of boiling water, the ozone 
will turn into 0. 

Properties. — Ozone is still more corrosive than oxy- 
gen. It bleaches powerfully, and is a rapid disinfect- 
ant. A piece of tainted meat plunged into a jar of it is 
instantly deodorized, and it is probable that, even in 
minute quantities, this gas exercises a powerful influence 
in purifying the atmosphere. Its over-abundance in the 
air is supposed to produce influenzas, diseases of the 
lungs, etc., and its absence to cause fevers, agues, and 
kindred diseases. 




* If a piece of the dry iodized paper be exposed upon a clear day in the open 
air of the country, in a few minutes it will assume a bluish tint. In cloudy, 
foggy weather, or in cities, this effect is rarely observed. 



Jfi INORGANIC CHE3IISTRY. 

Antozone (the opposite of ozone) is always formed 
at the same time as ozone, but returns to ordinary 
more readily. Its distinguishing trait is its tendency to 
form clouds with 0. We notice it in the oxidation of 
phosphorus, as a white mist which remains long after the 
phosphorus oxides have been dissolved by the H 2 0. The 
gray smoke that lingers around chimneys, steam-engines, 
etc., is composed of antozone. 

PRACTICAL QUESTIONS. 

1. Are all acids sour? 

2. What is the difference between an ate, an ite, and an ide 
compound ? 

3. Why does not canned fruit decay ? 

4. Where is the higher oxide formed, at the forge or in the 
pantry ? 

5. Why is the blood red in the arteries, and dark in the veins ? 

6. Do we need more in winter than in summer ? 

7. Which would starve sooner, a fat man or a lean one ? 

8. How do teamsters warm themselves by slapping their hands 
together ? 

9. Could a person commit suicide by holding his breath ? 

10. Why do we die when our breath is stopped ? 

11. Why do we breathe so slowly when we sleep ? 

12. How does a cold-blooded animal differ from a warm-blooded 
one? 

1 3. Why does not the body burn out like a candle ? 

14. Do all parts of the body change alike ? 

15. What objects would escape combustion if the air were undi- 
luted ? 

16. How much can be obtained from 6 oz. of KCIO^ ? 

17. How much KC10 3 would be needed to produce 2 lbs. of ? 

18. How much KC1 would be formed in preparing 1 lb. of ? 

19. Name a substance from which the can be set free by a 
stroke of the hammer. 

20. Name one from which the can only be liberated with 
extreme difficulty. 



NITB OG E N. 



Al 



21. Is it probable that all the'elements are discovered ? 

22. Is heat produced by oxidation? 

23. What is the difference between dynamic and potential 
force ? 

24. Why does running cause panting ? 

25. How does give us force ? 

26. Does the plant produce force ? 

27. If we burn an organic body in a stove it gives off heat ; in 
the body it produces also motion. Explain. 

28. In preparing N, a thin white cloud remains in the jar for a 
long time. What is it ? 



NITROGEN. 

Symbol, N Atomic Weight, 14. . . .Specific Gravity, 0,97, 

This gas is called nitrogen because it exists in nitre. 

Sources. — N forms \ of the atmosphere, and is found 
abundantly in ammonia, nitric acid, flesh,* and in such 
vegetables as the mushroom, cabbage, horse-radish, etc. 
It is an essential constituent of the valuable medicines, 
quinine and morphine, and of the potent poisons, prussic 
acid and strychnine. 

Preparation. — As the air consists 
of N and 0, the easiest method of 
obtaining the former gas is to remove 
the latter. Place in the centre of a 
deep dish of water a little stand sev- 



Fig. 8. 



era! inches in height, on which a 




Preparing N. 



bit of phosphorus may be laid and 

ignited. As the fumes of phosphoric anhydride ascend, 

invert a receiver over the stand. The phosphorus will 



* Its compounds give to burnt hair and woolen their peculiar odor. 



Jft INORGANIC CHEMISTRY. 

consume the of the air contained in the jar, leaving 
the N. Add more H 2 as that in the plate rises. It 
should occupy i of the receiver. The jar will at first be 
filled with white fumes (P 2 5 ), but they will be absorbed 
by the H 2 in a short time. 

Properties. — All descriptions of N are of a negative 
character. It neither burns nor permits anything else to 
burn. It neither supports life nor destroys it. Yet a 
candle will not burn in it, and a person cannot breathe 
it alone and live, simply because it shuts off the life- 
giving 0. So will a person drown in H 2 0, not that the 
water poisons him, but because it fills his mouth, and 
shuts out the air. N has only a weak affinity for any of 
the elements. The instability of its compounds is a strik- 
ing peculiarity. It will unite with iodine, for example, 
but a brush with a feather, or a heavy step on the floor 
will set it free.* 

Uses. — delation of N to Organic Substances. 
— Four-fifths of each breath that enters our lungs is N ; 
yet it comes out as it went in,f while that portion of the 
which remains behind performs its wonderful work 
within our bodies. One-fifth of our flesh is N, yet none 
of it comes from the air we breathe. Yv r e obtain all our 
supply from the lean meat and vegetables we eat. Plants 
breathe the air through the leaves — their lungs ; yet they 



* " Like a half-reclaimed gypsy from the wilds, it is ever seeking to be free 
again ; and not content with its own freedom, is ever tempting others, not of 
gypsy blood, to escape from thraldom. Like a bird of strong beak and broad 
wing, whose proper place is the sky, it opens the door of its aviary, and rouses 
and flutters the other and more peaceful birds, till they fly with it, although they 
soon part company."— Edinburgh Review. 

t There is a constant exhalation of N through the pores of the skin. This 
small amount is perhaps absorbed in the lungs, but it is of no use to the body, so 
far as known. 



KITROGEX. JfS 

do not appropriate any of the N obtained in this way, 
but rely upon the ammonia and the nitric acid their 
roots absorb from the soil. N enters the stove with the 
— the latter unites with the fuel ; but the former, having 
no chemical attraction, passes out of the chimney. Even 
from a blast furnace, where Fe melts instantly like wax, N 
comes forth without the smell of fire upon it (p. 150). So 
inert is it, that it will not unite directly with any organic 
substance. "We must all, animals and plants, depend 
upon finding it already combined in some chemical com- 
pound, and so appropriate it to our use. But even then 
we hold it very loosely indeed. The tendency of flesh to 
decompose is largely owing to the instability of the, N in 
its composition. 

^Difference between N and 0.* — We see now 
how different N is from 0. The one is the conservative 
element, the other the radical. But notice the nice 
planning shown in the adaptation of the two to our 
wants. 0, alone, is too active, and must be restrained ; 
N, alone, is sluggish, and only fit to weaken a stronger 
element. Were the air undiluted 0, our life would be 
excited to a pitch of which we can scarcely dream, and 
would sweep through its feverish, burning course in a 
few days ; were it undiluted N we could not exist a 
moment. Thus we see that, separately, either element of 
the air would kill us, by excess and N by lack of action. 

a?id N co?nbined. — A mixture of fiery and the 
inert N gives us the golden mean. The now quietly 



* The difference between these two gases can be best illustrated by having a 
jar of each, and rapidly passing a lighted candle from one to the other ; the N 
will extinguish the flame, and the relight the coal. By dextrous management, 
this may be repeated a score of times. 



44 



I NOR GANIC CHEMISTR Y. 



burns the fuel in our stoves and keeps us warm ; combines 
with the oil in our lamps and gives us light ; corrodes our 
bodies and gives us strength ; cleanses the air and keeps 
it fresh and invigorating ; sweetens foul water and makes 
it wholesome ; works all around and within us a constant 
miracle, yet with such delicacy and quietness that we 
never perceive or think of it until we see it with the eye 
of science. 

Compounds.— Nitric Acid, HN0 3 .* — Sources.— 
This acid is found in nature, combined with Na or K. 
It is formed in small quantities in the atmosphere by the 

Fig. 9. 




Preparing HN0 3 



union of its elements during the passage of electricity, as 
in a thunder-storm, and being washed to the earth by 
rain, is absorbed by the roots of plants. 

Preparation. — It is liberated by adding a stronger acid 
to one of the nitrates. Thus if sulphuric acid (H 2 S0 4 ) 
and sodium nitrate be heated together in a retort, the 



* The molecule of nitric anhydride is N 2 5 ; adding the elements of water, we 
have N 2 O s + H 2 - 2(HN0 3 ), or 2 molecules of nitric hydride (nitric acid). In 
Its compounds a metal takes the place of the H; thus, KN0 3 , NaN0 3 , etc. 



XITROGEK. ltd 

salt will be decomposed and the acid can be collected in 
a receiver, cooled by dripping water. 

Properties. — It is an intensely corrosive, poisonous 
liquid.* When pure, it is colorless ; but as sold, it has 
commonly a golden tint from the presence of a lower 
oxide of N, produced by the decomposing action of the 
light. It has been obtained in the form of brilliant 
transparent crystals (nitric anhydride), but they decom- 
pose spontaneously. In strength it is next to H 2 S0 4 . It 
was formerly called aqua-fortis, or strong water. It 
stains wood, the skin, etc., a bright yellow. It gives 
up its readily, and hence is a powerful oxidizing 
agent, f 

Uses. — HN0 3 i s employed in dyeing woollen yellow, 
and in surgery for cauterizing the flesh. It dissolves 
most of the metals, and in combination with H CI forms 
aqua-regia, the usual solvent of Au. It etches the lines in 
copperplate engraving, and the beautiful designs on the 
blades of razors, swords, etc. The process is very simple. 
The surface is covered with a varnish impervious to the 
acid, and the desired figure is then sketched in the var- 
nish with a needle. The H N0 3 being poured on, oxidizes 
the metal in the delicate lines thus laid bare. 



* This fact shows the power of chemical affinity. The bland mixture we in- 
hale at every breath is changed to a corrosive poison, 
t The following experiments illustrate this property of HjSTOs : 

1. Mix equal parts of strong HN0 3 and H 2 S0 4 . Place a little oil of turpen- 
tine in a cup out-of-doors, and pour the mixture upon it at arm's length. The 
turpentine will burn with almost explosive violence. 

2. Pour very dilute HN0 3 upon bits of tin. Dense, red fumes CN"0 2 .hyponitric 
anhydride) will pass off, and the Sn will be converted into a white oxide, which 
furnishes what is termed putty powder. 

3. Throw crystals of any nitrate on red-hot coals. They will deflagrate on 
account of the O which they give up to the fire. 

4. Soak a strip of blotting-paper in a solution of nitre. It will form " touch* 
paper," and when lighted will orily smoulder. 



w 



1N0R GANtC CMEM1STR T. 



Nitrous Oxide, N 2 0. — Preparation. — This gas is 
made by heating ammonium nitrate (H 4 N,N0 3 ), which 
decomposes into H 2 and N 2 0. (See p. 135.) 

Fig. 10. 





Preparing N 2 0. 



Properties. — N 2 is a colorless, transparent gas with a 
faintly sweetish taste and smell. It supports combustion 
nearly as well as 0, and many of the experiments 
ordinarily performed with that gas will be equally bril- 
liant with N 2 0. If breathed for a short time, it produces 
a peculiar kind of intoxication, often attended with un- 
controllable laughter, and hence it has received the 
popular name of laughing gas. The effect soon passes 
off. If taken for a longer time, it causes insensibility, 
and is therefore valuable as an anaesthetic in surgical and 
dental operations. 

Nitric Oxide, NO. — Preparation. — This gas may be 
prepared by the action of dilute HN0 3 on copper clip- 
pings. The flask (a, Fig. 11) will soon be filled w T ith red 
fumes, but a colorless gas will collect in the jar over 
water. At the conclusion of the process, the flask will 



NI T R G EN. 



47 



contain a deep blue solution of copper nitrate (Cu2N0 3 )u 
By filtering and evaporating, the beautiful crystals of 
this salt may be obtained. 



Fig, 11. 




8HNO0 




3(Cu2N0 3 ) + 4H 2 + 2NO 



Preparing NO. 

Properties.— NO is a colorless, irrespirable gas with a 
disagreeable odor. Its remarkable property is its affinity 
for 0. Let a bubble escape into the air, and red fumes 
of hyponitric anhydride (N0 2 ) will be formed.* 

Ammonia, H 3 N. — Source. — This gas was formerly 
called hartshorn, because in England it was made from 
the horns of the hart. It received the name ammonia, 
by which it is now more generally known, from the tem- 
ple of Jupiter Amnion, near which sal-ammoniac, one of 
its compounds, was once manufactured. The aqua- 

* This may be illustrated still more prettily by the following experiment : — 
Fill a small jar with water colored blue by litmus solution, and pass up into it 
sufficient NO to occupy about one-third of the bottle ; the litmus will not change 
in color. Now allow a few bubbles of to rise into the NO ; deep red fumes 
will be formed, which will quickly dissolve, and the blue solution become red. 
If both the and the NO be pure, it is possible, by cautiously adding 0, to 
cause a complete absorption of both gases. If common air were used instead of 
O, only N would then remain in the jar. 



# 



IN OR G ASIC CHEjIISTR T. 



ammonia of the shops, which is merely a strong solution 
of the gas in H 2 0, is obtained from the incidental pro- 
ducts of the gas-works in large quantities. (See p. 83.) 
Its pungent odor can often be detected near decaying 
vegetable and animal matter. 

Preparation. — H 3 N is ordinarily prepared by heating 
sal-ammoniac with liine.* The stronger base unites with 

Fig. 12. 




H^X burning In O. 



the CI, and sets the ammonia free. The reaction may 
be shown as follows : 



2(H 4 N, CI) + CaO 



2 H 3 N, H 2 + CaCl 2 

Properties. — Water at 60° F. will absorb 700 times its 
own bulk of the gas.f This solution will produce a 
blister, and should, therefore, be very much weakened 

* This may "be illustrated by simply mixing in a cup some powdered sal- 
ammoniac and lime, when the ammonia may be detected by its odor, and the 
bluing of moist red litmus-paper. 

t Heat a little aqua ammonia in a Florence flask. Dry the vapor and collect 
in an inverted bottle, to which is fitted a cork and tube, with the inner extremity 
drawn to a fine point over the spirit-lamp. Insert the cork, and then plunge the 
bottle into a vessel of water. The water which passes in first will absorb the 
gas so quickly as to make a partial vacuum, into which the water will rush sc 
violently as to produce a miniature fountain. 



NITROGEN. W 

before being tasted or touched. It is a strong alkali, and 
turns the vegetable blues to green; but owing to its 
volatility this change of color is only temporary. It is, 
therefore, sometimes termed " the volatile alkali." It 
neutralizes the most powerful acids, and forms important 
salts. Its vapor burns in with a green flame. (See 
Fig. 12.) Its test is HC1. — Example : If we bring a stopple 
wet with HC1 near this gas, it will instantly reveal itself 
by a dense cloud of white fumes, ammonium chloride 
(sal-ammoniac), which floats in the air like smoke. The 
antidote of H 3 N is vinegar. Gaseous ammonia becomes 
liquid at a cold of —40°. 

JYascenl Slate. — If N and H, the elements of H 3 N, 
be mixed in a receiver, they will not unite chemically, 
owing to the negative character of N. When, however, 
any substance is decomposed which contains both of 
them, as bituminous coal, flesh, etc., at the very instant 
of their separation they will combine and form H 3 I\L 
When elements are thus in the act of leaving their com- 
pounds, they are said to be in their " nascent state." 

PRACTICAL QUESTIONS.. 

1. How could you detect any free in a jar of N ? 

2. How would you remove the product of the test ? 

3. In the experiment shown in Fig. 11, why is the gas red in the 
flask, but colorless when it bubbles up into the jar ? 

4 How much H 3 N can be obtained from 3 lbs. of sal-ammoniac ? 
5. How much H 2 will be formed in the process? 
G. How much CaO will be needed? 

7. In separating N, how much air will be needed to furnish a 
gallon of the gas ? 

8. How much N 2 can be made from 1 lb. of ammonium nitrate? 

9. How much nitric acid can be formed from 50 lbs. of sodium 
nitrate (NaNO :J )? 



60 INORGANIC CHEMISTRY, 

10. What causes flesh to decompose so much more easily than 
wood ? 

11. If a tuft of hair be heated in a test tube, the liquid formed 
will turn red litmus-paper blue. Explain. 

12. Why should care be used in opening a bottle of strong H 3 N 
in a warm room ? 

13. What weight of N is there in 10 lbs. of HN0 3 ? 

14. How much sal-ammoniac would be required to make 2 lbs. 
of H 3 N? 

15. Give illustrations of the replacement of the H in an acid by 
a metal. 

16. What is the difference between liquid ammonia and liquor 
ammoniae ? 



HYDROGEN. 

Synjbol, H . . .Atomic Weight, 1 Specific Gravity ,069. 

Hydrogen means literally a generator of water. 
Preparation. — It is always obtained by the decompose 

Fig. is. 



Preparing hydrogen. 



tion of H 2 0, of which it forms i part by weight. If we 
place in an evolution flask (a common junk bottle will 



HYDROGEN. 51 

answer) bits of Zn, and then pour through the funnel 
tube (b) H 2 and H 2 S0 4 , the gas will be evolved abun- 
dantly. (See Appendix.) The reaction is as follows: 




ZnS0 4 



The Zn simply takes the place of the H 2 . The black 
specks floating in the liquid are charcoal from the zinc, 
The milky look is given by the zinc sulphate (white 
vitriol) which is formed. By evaporating the water, the 
crystals of this salt may be obtained. 

Properties. — H prepared in this manner has a disagree- 
able odor, from various impurities in the materials used. 
When pure, it is, like 0, colorless, transparent, and odor- 
less. H has the greatest diffusive power of any element ; 
and in attempts made to liquefy the gas, it leaked 
through the pores of the thick iron cylinders in which 
it was compressed. It is the lightest of all bodies, being 
only j 1 ^ as heavy as common air. It is not poisonous, 
although, like N, it will destroy life or combustion by 
shutting out the life-sustainer, 0. When inhaled, it 
gives the voice a ludicrously shrill tone. Tt can be 
breathed for a few moments with impunity, if it be first 
passed through lime-water to purify it. (See Fig. 13.) 
Owing to its lightness, it passes out of the lungs again 
directly. Its levity suggested its use for filling balloons,* 



* We read in accounts of fetes at Paris, of balloons ingeniously made to repre' 
sent various animals, so that aerial hunts are devised. The animals, however, 
persistently insist upon ascending with their feet up — a circumstance productive 
of great mirth in the crowd of spectators. 



52 



INOR GANIC CHE31ISTR Y. 



Fig. Ik. 




Fig. 15 



Candle in H. 



and it has been employed for that purpose ; but co&i 
gas, which contains much H, and is cheaper, is now 
preferred. 

Combustion of H. — A lighted candle, plunged into 
an inverted jar of H, is extinguished, while 
the gas itself takes fire, and burns with a 
feeble flame. One atom of the of the 
air unites with two atoms of the H, and 
the product of the combus- 
tion is H 2 0, which maybe 
condensed on a cold tum- 
bler, held over a jet of the 
burning gas. (See Fig. 16.) 
The Philosopher's Lamp (see 
Fig. 15) is a more simple 
means of illustrating the properties of H. 

M^ixed Gases. — A mixture of two 
parts, by measure, of H, with one part of 0, or 
five parts of common air, when ignited, will 
explode violently.* The heat generated by 
the union of H 2 and 0, expands into steam 
the drop of H 2 thus formed. Immediately 
after, the steam being condensed, a vac- 
uum is produced and the particles of air rushing in to 
fill the empty space, by their collision against each other, 
cause the deafening sound. While the detonation is 
so great, the force is slight, as may be shown by explod- 
ing, in the hand, soap-bubbles blown with the gases. H 




The Philoso- 
pher's Lamp. 



* The H gun— which is simply a tin tube, closed at one end, and provided with 
a cork at the other, having a priming-hole at the side— is used to illustrate this 
fact. It may be filled over the Philosopher's Lamp when that is not ignited. 
The gas is allowed to pass in until the gun is about a fifth full, as nearly as one 
can guess, when the gun is removed and the gases ignited at the priming-hole. 




58 



H a formed by burning H. 



and may be mingled in the right proportion for combus- 
tion, and though kept for years, there will be no change. 



Fig. 17. 




Transferring gases. 



5b 



INORGANIC CHEMISTRY. 



Fig. 18. 



The different atoms lie against one another quietly, with 
no manifestation of their chemical affinity, until sud- 
denly, at the contact of the merest spark of fire, they 
rush together with a crash like thunder, and uniting, 
form the bland, passive liquid — water. 
Aclio?i of Spo?igy (Plali?itim . —A piece of spongy 
platinum placed in a jet of H will ig- 
nite it. This curious effect seems to be 
produced in the following way: The 
atoms of H and the of the air are 
brought so closely together in its minute 
pores that they unite, and the heat thus 
generated sets fire to the gas. This 
action is nicely shown by the instru- 
ment represented in Fig. 18. It w&s 
formerly used by chemists as a conven- 
ient way of obtaining a light in the 
laboratory. Friction matches have superseded this inge- 
nious invention. 

Jleal of Sti?*?ii?ig H. — A hydrogen flame gives lit- 
tle light, but great heat. In H and 0, existing as gases, 
there is stored a vast amount of latent energy. (Physics, 
pp. 36, 185.) When they unite by chemical affinity, this 
force is set free. "In the union of 16 lbs. of and two 
of H, sufficient potential force is developed to raise 
40,000,000 lbs. a foot high." 
JTydrogen Tones. \ — A singular illustration of the 

* Z is a piece of zinc suspended in a mixture of H 2 S0 4 and H 2 0. At the top 
is a stop-cock, by turning which the gas is allowed to pass out from the re- 
ceiver /. It strikes upon a piece of spongy platinum, and ignites with a slight 
explosion. 

t Another illustration of singing hydrogen may be represented in the follow- 
ing manner : Make a jar of heavy tin, in the form of a double cone, 12 inches 
long and 4 inches in diameter. At one apex fit a nozzle and cork ; at the other, 




Dobereiner's Lamp. 



M YD MO G EN. 



55 



laws of sound can be given by simply holding a long 
glass tube, by means of a suitable clamp, over a minute 
jet of burning H. 
At first no effect 
will be produced; 
but as Ave slowly 
introduce the jet 
further and fur- 
ther into the tube, 
a faint sound is 
heard, apparently 
in the far-off dis- 
tance. It gradu- 
ally approaches, 
and finally bursts 
into a shrill, con- 
tinuous, musical 
note — the key- 
note of the heated 
column of air 
within the tube. 
The flame is mo- 
mentarily extin- 
guished and r e- 
lighted with a 
slight explosion, 
the rapid repetition of which is supposed 




Hydrogen tones. 



to produce 



make several minute openings. Cover the holes with sealing-wax, and draw 
the cork ; then fill the jar with H, and replace the cork. When ready for use, 
hold the jar in a vertical position, remove the wax from at least one orifice, 
ignite the H at that point, and draw the cork. Still hold the jar quietly, and in a 
minute or two the tiny jet of H will begin to sing like a swarm of mosquitoes, 
buzzing and humming in a most aggravating way until, unexpectedly, the scien- 
tific music ends in a loud explosion. 



56 INORGANIC CHEMISTRY. 

the musical note. Indeed, the explosions may be made 
so slow that the quivering of the flame- can be seen, 
and the sound cease to be continuous as before. Let 
us now place the tube at a point where no clapping 
of hands or unusual sound will start it into song. Let 
various tones be produced from a violin, and we shall 
find the flame responding only to that tone which is the 
key-note of the tube, or its octave. The violin player 
will have perfect control of this scientific music, and can 
start, stop, or throw it into violent convulsions, even 
across a large hall. Tubes of different sizes and lengths 
will give tones of diverse character and pitch.* The 
waves of sound from the instrument augmenting or in- 
terfering with those in the tube probably produce these 
phenomena. (See Physics, p. 141.) 

WATER. 

The composition of H 2 is proved by analysis and 
synthesis — i. e., by separating the compound into its 
elements, and by combining the elements to produce the 
compound. We can analyze it in the manner already 
shown in preparing H, or by passing through it a gal- 
vanic current, when the will appear in bubbles of gas 
at the positive pole, and the H in a similar way at the 
negative. In the synthetic method, we mix the two 
gases, and unite them as we have before by an electric 
spark. The blacksmith decomposes water when he sprin- 
kles it on the hot coals in his forge. The H burns with a 

* The singing of the hydrogen flame may be illustrated more simply by hold- 
ing the beaks of broken retorts, or large tubes of any kind, over the flame of the 
Philosopher's Lamp. Jets of different sizes may be made by drawing out glass 
tubing over the spirit-lamp. 



WA TE R. 



57 




Analysis of water. 



pale flame, while the in- Fig. 20. 

creases the combustion. Thus, 

in a fire, if the engines throw 

on too little water, it may be 

decomposed, and add to the 

fury of the flame.* To " set 

the North River on fire" is 

only a poetical exaggeration. 

The quantity of electricity 
required to decompose a sin- 
gle grain of water is estimated to be equal to a power- 
ful flash of lightning. The enormous force necessary to 
tear these two elements from each other shows the won- 
derful strength of chemical attraction, f ' We thus see, that 
in a tiny drop of dew there slumbers the latent power of 
a thunderbolt. 

Water i?i the &?iimal World. — The abundance 
of water very forcibly attracts the attention. It composes 
perhaps § of our flesh and blood. Man has been facetiously 
described as 12 lbs. of solid matter wet up in six pails of 
water. All plumpness of flesh, and fairness of the cheek, 
are giyen by the juices of the system. A few ounces of 
water and a little charcoal constitute the principal chemi- 
cal difference between the round, rosy face of sixteen, 



* " No more heat is produced by the action of the H 2 0. but it is in a more avail- 
able form for communicating heat. The steam in contact with incandescent 
charcoal is decomposed— the O going to the C to form C0 2 , and the H being set 
free. If the C is abundant, and the heat high, the C0 2 is also decomposed, and 
double its volume of CO formed. The inflammable gases. H and CO, mingled 
with the hydrocarbons always produced, are ignited, making the billows of flame 
which sweep over a burning building.'"— S. P. Sharples. 

t The force needed to separate them becomes latent in the gases as a potential 
force, and when they are burned at any time will be set free as sensible heat— 
a dynamic force. 



58 INORGANIC CHEMISTRY. 

and the wrinkled, withered features of three-score and 
ten. To supply the constant demand of the system for 
water, each adult, in active exercise, needs about three 
pints per day, or over half a ton annually. (See Phys- 
iology, p. 220.) When we pass to lower orders of animals, 
we find this liquid still more abundant. Sunfishes are 
little more than organized water. Professor Agassiz 
analyzed one found off the coast of Massachusetts, which 
weighed 30 lbs., and obtained only half an ounce of dried 
flesh. Indeed, naturalists state that an entire class of 
animals (hydrozoa), to which belong the jelly-fish, medusa, 
etc., is composed of only ten parts in a thousand of solid 
matter. (See Zoology, p. 269.) 

Water in the Yegetabte World. — In the vege- 
table world we find it abundant. Wood is composed of 
G parts charcoal and 5 parts water, with a little mineral 
matter comprising the ashes. Bread is half water ; and 
of the potatoes and turnips cooked for our dinner, it 
comprises 75 parts of one and 90 of the other. The fol- 
lowing table shows the proportion in common vegetables, 
fruits, and meats : 

Mutton 71 Trout 81 Cabbage 92 

Beef 74 Apples 80 Cucumbers. . . .97 

Veal 75 Carrots 83 Watermelons .98 

Pork 76 Beets 88 

Water i?i the Mine?*al World . — Bodies in which 
the water is chemically combined in definite proportions, 
are often called hydrates. In the image which the Italian 
pedler carries through our streets for sale, there is nearly 
1 lb. of H 2 to every 4 lbs. of plaster of Paris. One- 
third of the weight of any ordinary soil is this same 



WA T E R. 59 

liquid. Each pound of strong nitric acid contains 2f oz. 
of water, which, if removed, would destroy the acid itself. 
If we expel the water from oil of vitriol, it will lose its 
acid properties, and we can handle it with impunity. In 
bodies which are capable of crystallizing, it seems to 
determine the form and general appearance, and is called 
"the water of crystallization." If we evaporate this from 
blue vitriol, it will lose its color and become white like 
flour.* A few drops of H 2 will restore the blue. If we 
expel this from alum, it will puff up, and the transparent 
crystals will dry into an incoherent mass. Many salts 
effloresce, i. e., part with their water of crystallization on 
exposure to the air, and crumble into a white powder. 

Water as a Solvent. — Water, having no taste, col- 
or, or odor itself, is perfectly adapted to be the universal 
solvent. It becomes at pleasure sweet, sour, salt, bitter, 
nauseous, and even poisonous. Had water any taste, the 
whole science of cookery would be changed, since each 
substance would partake of the one universal watery 
flavor. 

"Pure Wate?\ — Kain-water, caught after the air is 
thoroughly cleansed by previous showers, and at a dis- 
tance from the smoke of cities, is the purest natural 
water known. It is tasteless, yet its insipidity makes it 
seem to us very ill-flavored indeed. We have become so 
accustomed to the taste of the impurities in hard water, 
that they have become to us tests of its sweetness and 
pleasantness. 

ffiiver Water, though it may have less mineral mat- 

* This may be easily shown by filling the bowl of a tobacco-pipe with crystals 
of the salt, and heating them over a lamp or in the fire until the water of crys- 
tallization is expelled. Alum may be made anhydrous in the same way. 



60 INOBGAJSTIC CHEMISTRY. 

ter than spring water, is often unfitted for drinking on 
account of the organic matter it contains. Happily, run- 
ning water has in itself a certain purifying power, owing 
to the air which it holds in solution ; so that, paradoxical 
as it may seem, organic substances are burned in it as cer- 
tainly as they would be in a stove. Still, in order to avoid 
any danger, river water should be filtered through char- 
coal or sand before using.* 

JETard Water. — As water percolates through the 
soil into our wells, it dissolves the various mineral mat- 
ters characteristic of the locality. The most abundant 
of these are lime,f salt, and magnesia. The former pro- 
duces a fur or coating on the bottom of our tea-kettles, 
if we live in a limestone region. When we put soap in 
such water, it curdles — i. e., it unites with the lime (CaO), 
forming a new, or lime soap, which is insoluble in H 2 0. 
H 2 containing an excess of mineral matter is unwhole- 
some ; yet it is probable that the sparkling hard waters 
of the limestone districts are relished, not only because 
they are pleasant to the eye and agreeable to the taste, 
but on account of some hygienic properties in the excess 
of CO 2 they contain, and possibly because the CaO acts 
medicinally on the system.]; 

* A weak solution of potassium permanganate is an excellent test of the 
presence of organic matter. Place the water to be examined in a glass, and add 
a little permanganate ; if organic matter is present the violet permanganate solu- 
tion is decolorized as fast as added until all the organic matter is oxidized. 

t It is a fact worthy of note that lime and oxide of iron, which are frequently 
found in H 3 0, the latter generally in minute quantities, are both healthful; while 
the oxides of the other metals are poisonous. Were zinc or barium, for instance, 
as common near our homes as iron or calcium, wholesome drinking water would 
be rarely, if ever, found. By a wise arrangement of an ever-watchful Provi- 
dence, those dangerous metals are rare, and hidden far from the haunts of man. 

% The French authorities are so well satisfied of the superiority of hard water, 
that they pass by that of the sandy plains, near Paris, and go far away to the 
chalk hills of Champagne, where they find water even harder than that of Lon- 



WATER. 61 

Sea - JKater. — The most abundant mineral in the 
ocean is common salt. Yet it contains traces of every 
substance soluble in water, which has been washed into 
the sea from the surface of the continents during all the 
ages of the past. Its saline constituents are now in the 
proportion of about \ oz. to 1 lb. This amount may 
be slowly increasing, as the water which evaporates from 
the surface is comparatively pure, containing only a mere 
trace of a few substances, which give to the sea-breeze its 
peculiar bracing, tonic influence. In this way, the water 
of the Salt Lake has become a strong brine, nearly 
\ of its whole weight consisting of saline matter. This 
condition would soon disappear if an outlet could be 
provided. 

Water jltmosp7ie?*e. — As the world of waters is 
inhabited, it also has its atmosphere.* Inasmuch as the 
H 2 dilutes the in part, it does not need so much N 
as the common air. It is accordingly composed of over 
I instead of only i. The air so rich in thus absorbed 
by the water gives to it life and briskness. If it be ex- 
pelled by boiling, the water tastes flat and insipid. 

"Paradoxes of Water. — "Cold contracts," is the 
law of physics; but as H 2 cools, it obeys this principle 
only as far as 39° F. Then it slowly expands, cooling 
down to 32°, its freezing point, when its crystals sud- 
denly dart out at angles to each other, and thus, increas- 



don ; giving as a reason for the preference that more of the conscripts from the 
soft-water districts are rejected on account of the want of strength of mus- 
cle, than from the hard-water districts ; from which they conclude that the cal- 
careous matter is favorable to the formation of the tissues. 

* Fish inhale O through the fine silky filaments of their gills. When a fish 
is drawn out of H 2 0, these dry up. and it is unable to breathe, although it is 
in a more plentiful atmosphere than it is accustomed to enjoy. 



62 J X ORGANIC CKEMISTR Y. 

ing in size about ^ Y , it congeals to ice. By this wise ar- 
rangement, ice is lighter than water, and so swims on top ; 
otherwise our rivers would freeze solid, killing the fish 
and aquatic plants. The longest summer could not melt 
such an immense mass of ice. But now the blanket that 
Nature kindly weaves over the rivers and ponds keeps 
their finny inhabitants warm and comfortable till spring ; 
then she floats it south to melt under a hotter sun. We 
give to water such contradictory terms as " hard " and 
" soft," " fresh " and " salt," H 2 seems the most yield- 
ing of substances, yet the swimmer who falls on his face, 
instead of striking head foremost, appreciates the mis- 
take, and we could drive a nail into a solid cube of steel 
as easily as into a hollow one perfectly filled with H 2 0. 
H is the lightest substance known, and is an invisible 
gas ; yet they unite and form a liquid whose weight we 
have often experienced, and a solid which makes a pave- 
ment hard like granite. H burns readily, and, when 
mixed with 0, explodes most fearfully ; supports com- 
bustion brilliantly — yet the two combined are used to 
extinguish fires. H or in excess w^ould destroy life ; 
H 2 is so essential to it that thirst causes a lingering, 
painful death. * 

Uses of Wale?\ — The uses of H 2 are as diverse 
as they are practical. Its properties fit it for a wonderful 
variety of operations in nature. Its office is not merely 
to moisten our lips on a hot day, to make a cup of coffee, 
to lay the dust in the street, and to sprinkle our gar- 
dens ; it has grander and more profound uses than any 
of these. Water is the common carrier of creation. It 
dissolves the elements of the soil, and, climbing as sap 
up through the delicate capiHary tubes of the plant, 



WATER. 63 

furnishes the leaf with the materials of its growth. It 
flows through the body as blood, floating to every part 
of the system the life-sustaining 0, and the food neces- 
sary for repairs and for building up the various parts of 
the " house we live in." It comes in the clouds as rain, 
bringing to us the heat of the tropics, and tempering our 
northern climate, while in spring it floats the ice of our 
rivers and lakes away to warmer seas to be melted. It 
washes down the mountain side, levelling its lofty sum- 
mit and bearing mineral matter to fertilize the valley 
beneath. It propels water-wheels working forges and 
mills, and thus becomes the grand motive-power of the 
arts and manufactures. It flows to the sea, bearing on 
its bosom ships conducting the commerce of the world. 
It passes through the arid sands, and the desert forth- 
with buds and blossoms as the rose. It limits the bounds 
of fertility, decides the founding of cities, and directs the 
flow of trade and wealth. 

PRACTICAL QUESTIONS. 

1. Why, in filling the hydrogen gun, do we use 5 parts of com- 
mon air to 2 of H, and only 1 part of to 2 of H ? 

2. Why are coal cinders often moistened with H 2 before 
using ? 

3. What injury may be done by throwing a small quantity of 
H 2 on a fire? 

4. Why does the hardness of water vary in different localities ? 

5. What causes the variety of minerals in the ocean? Is the 
quantity increasing ? 

6. Is there not a compensation in the sea-plants, fish, etc., which 
are washed back on the land ? 

7. Since " all the rivers flow to the sea," why is it not full ? 

8. What is the cause of the tonic influence of the sea breeze ? 

9. When fish are taken out of the water, and thus brought into 
a more abundant atmosphere, why do they die ? 



04 INORGANIC CHEMISTRY. 

10. Do all fish die when brought on land ? 

11. What weight of water is there in a cwt. of sodium sulphate 
(Na 2 S0 4 , 10H 2 O), or Glauber's salt? 

12. What weight of water in a ton of alum (KAI2S0 4 , 12H 2 0) ? 

13. How much water would it require to change 5 lbs. of nitric 
anhydride to nitric acid ? 

14. How does the air purify running water ? 

15. What is the action of potassium permanganate as a disin- 
fectant ? 

16. Why does lime sometimes soften hard water when added 
to it? 

17. What weight of H can be obtained from a gallon of water ? 

18. In decomposing H 2 0, 65 parts by weight of Zn yield 2 parts 
by weight of H. How much Zn must be employed to obtain 100 
lbs. of H ? 

19. How much KC10 3 would be required to evolve sufficient to 
burn the H produced by the decomposition of 2 lbs. of H 2 ? 

* 20. How much would be required to oxidize the metallic Cu 
which could be reduced from its oxide by passing over it, when 
white-hot, 20 gr. of H gas ? 

21. How much would be required to oxidize the metallic Fe 
which could be reduced in the same manner by 10 grs. of H gas? 

22. Why are rose-balloons so buoyant ? 

23. How much H must be burned to produce a ton of water ? 



CARBON. 



Symbol, C. Atomic Weight, 12, Specific Gravity of Dianjond,3.3to 3.5. 

Source. — C is one of the most abundant substances in 
nature, forming nearly one-half of the entire vegetable 
kingdom, and being a prominent constituent of lime- 
stone, corals, marble, magnesian rocks, etc. We find it 
in three distinct forms or allotropic conditions — viz., the 
diamond, graphite, and amorphous carton. This last 
term means without crystalline form, and includes gas- 



CARBON. 65 

carbon, charcoal, lamp-black, coal, coke, peat, soot, bone- 
black and ivory-black. In each of these various sub- 
stances C possesses different properties ; yet any impuri- 
ties it may contain seem entirely incidental, and not at 
all necessary to its new state. ♦ 

'Proof of this Allotropic stale. — Chemists have 
changed most of these substances into other allotropic 
forms. Thus, common charcoal has been turned into 
graphite, mineral coal into gas-carbon, the diamond into 
coke. All of them, when heated in the open air, unite 
with the same quantity of 0, forming precisely the same 
compound — carbonic anhydride — from which the C can 
be obtained again in the form of charcoal. 

The H)iamond is pure carton crystallized. It is 
the hardest of all known substances, scratches all other 
minerals and gems, and can be cut only by its own dust. 
It is infusible, but will burn at a high temperature. 
It is found in various parts of the world — North Carolina, 
Georgia, Borneo, Brazil, and South Africa. In 1858, 
Brazil furnished 120,000 carats.* They usually appear 
as semi-transparent, rounded pebbles, enclosed in a thin, 
brownish, opaque crust, which being broken reveals 
the brilliant gem within. They are of various tints, 
though often colorless and perfectly transparent. The 
last are most highly esteemed, and, from their resem- 
blance to a drop of clear spring- water, are called diamonds 
of the " first water." They are exceedingly brittle, and 
valuable gems are said to have been broken by simply 



* A carat is equal to 4 grs. Troy. The term is derived from the name of a bean 
which, when dried, was formerly used in weighing by the diamond merchants 
in India. 




66 INORGANIC CHEMISTRY. 

falling to the floor. Nothing definite is known concern- 
ing the origin of this gem.* 

The 1)iamo7id is Ground by means of its own 
powder. Being fitted to the end of a stick or handle, it 
is pressed down firmly against the face of a rapidly re- 
volving wheel, covered with dia- 
mond-dust and oil. This, by its 
friction, removes the exposed edge 
and forms a facet of the gem. 
There are three forms of cutting — 

The brilliant. The rose. ° 

the brilliant, the rose, and the table. 
The brilliant has a flat surface on the top, with facets at 
the side, and also below, the latter terminating in a 
point, so arranged as to refract the light most brilliantly. 
This form shows the gem to the best advantage, but is 
used only in large, thick stones, as it sacrifices nearly 
half the weight in cutting. The rose is flat beneath, 
while the upper surface is ground into triangular facets, 
terminating at a common vertex. The table form is em- 
ployed for thin specimens, which are merely ornamented 
by small facets on the edge. The diamond is valued not 



* Although the diamond is simply pure carbon, yet it has never been made by 
any chemical process. Minute diamonds, it is said, have been separated from 
carbon compounds by long-continued voltaic action, but they were invisible ex- 
cept with a microscope. The value of the diamond varies with the market ; the 
general rule is as follows : a gem ready for setting, of one carat weight, is worth 
$150 to $180 ; beyond this size, the estimated value increases according to the 
square of the weight, but in case of large stones is generally much less than that 
amount, although rare beauty or size may greatly enhance the price. The Kohi- 
noor (mountain of light, now among the crown jewels of England) weighs 103 
carats, yet is valued at $10,000,000. Owing to the discovery of many large dia- 
monds in South Africa, the value of such stones has much decreased of late. 
The smaller ones, however, are becoming more expensive on account of the 
greater demand for them. The South African diamonds are seldom colorless, 
having generally a yellowish tint. Paste diamonds are now made in Paris, 
which are so perfect an imitation that only experts can distinguish them from 
the real gems. 



CAR BOX. 67 

alone for its rarity and high refractive power, by which 
it flashes such vivid and brilliant colors, but also for its 
mechanical uses. For cutting glass, the curved edges of 
the natural crystal are used. 

Grap/iile or ^Plumbago is also called black-lead, 
because on paper it makes a shining mark like lead. It 
is found at Ticonderoga, N". Y., Brandon, Yt., and Stur- 
bridge, Mass. It is supposed to be of vegetable origin. 

Uses. — It is chiefly useful in pencils. For this pur- 
pose a mixture of black-lead, antimony, and sulphur — 
the proportion of these ingredients determining the 
hardness of the pencil — is melted and cast into blocks, 
which are then sawed into thin slips, as seen in com- 
mon pencils.* Though graphite seems very soft, yet its 
particles are extremely hard, and the saws used in cut- 
ting it soon wear out. We notice this property in sharp- 
ening a pencil with a knife. Graphite mixed with clay 
is made into black-lead crucibles. These are the most 
refractory known, and are used for melting gold and 
silver. It is also sold as " British lustre/' " carburet of 
iron," " stove polish," etc., which are employed for black- 
ing stoves and protecting iron from rusting. 

Gas-Carbo?i is formed on the interior of the re- 
torts used in coal-gas works. It has a metallic lustre, 
and will scratch glass. 

Cliarcoal is made by burning piles of wood, so 
covered over with turf as to prevent free access of air. 
The volatile gases, water, etc., are driven off, and the C 

* For drawing-pencils, pure graphite powder is subjected to such enormous 
pressure that the particles are brought near enough together for the attraction 
of cohesion to hold them in a solid form, when the pressure is removed. This 
block is then sawed into prisms, which are fitted into cylinders of cedar- 
wood. 



68 



IN OR G A NIC CHEMISTRY, 



left behind. This forms about f of the bulk of the wood 
and \ its weight. Charcoal for gunpowder and for medi- 



Fig. 22. 




Making charcoal. 

cinal purposes is prepared by heating willow or poplai 
wood in iron retorts. 

Properties. — It is the most unchangeable of all the ele- 
ments, so that even in the charcoal we can trace all the 
delicate structure of the plant from which it was made. 
It is insoluble in any ordinary liquid. None of the acids, 
except nitric, corrodes it, No alkali will eat it, Neither 
air nor moisture affects it. Wheat has been found in the 
ruins of Herculaneum that was charred 1800 years ago, 
and yet the kernels are as perfect as if grown last harvest 
The ground ends of posts are rendered durable by char- 



C A R B lY. by 

ring. Indeed, some were dug up not long since in the 
bed of the Thames which were placed there by the an- 
cient Britons to oppose the passage of Julius Caesar and 
his army. A cubic inch of fine charcoal has, it is said, 
100 feet of surface, so full is it of minute pores. These 
absorb gases by capillary attraction to an almost incredi- 
ble extent. A bit of C will take up 90 times its bulk of 
ammonia. As the various gases and the of the air are 
brought so closely together within its pores, rapid oxida- 
tion is produced, as in the case of spongy platinum (see 
p. 54). Pans of charcoal soon purify, and sweeten the 
offensive air of a hospital. Foul water filtered through C 
loses its impurities. Beer by this process parts not only 
with its color but with its bitter taste. Ink is robbed 
of its value and comes out clear and transparent as 
water. v 

'Deoxidizing or deducing Action of C. — At 
a high temperature the attraction of C for is powerful. 
In the heat of a furnace it will take it from almost the 
stablest compounds. This fact gives to charcoal great 
value in the arts. Nearly all the metals and many of the 
other elements are locked up in the rocks with 0, and 
C is the key made by the Creator for unlocking the 
treasure-houses of nature for the supply of our wants. 
By noticing the process of preparing zinc, iron, phospho- 
rus, etc., we shall see the importance of this property of 
C. A very pretty illustration is shown 
by placing a few grains of litharge 
(PbO) on a flat piece of charcoal, and 
directing upon it the flame of a blow- 
pipe. The metal will immediately ap- 

x x J r PbO on charcoal. 

pear in little sparkling globules. 




70 INORGANIC CHEMISTRY. 

Soot is unburnt carbon which passes off from a lamp 
or fire when there is not enough present to combine 
with all the C of the fuel. This, therefore, comes away 
in flakes, and blackens the chimney of the lamp, or lodges 
in the chimney of the house. After a time, a large 
quantity haying collected, we are startled by the cry, 
" The chimney is on fire ! " while with a great roar and 
flame the soot burns out. This unpleasant occurrence is 
much more frequent when green wood is used for fuel. 
The H 2 of the wood absorbs much of the heat of the 
fire, and so permits the C to pass off unconsumed. 

Z/ampblacfb is obtained by imperfectly burning pitch 
or tar. The dense cloud of smoke is conducted into a 
chamber lined with sacking, upon which the soot collects. 
It is largely used in painting. It is mixed with clay to 
form black drawing-crayons, and with linseed oil to make 
printers' ink. Lampblack has peculiar properties which 
fit it for printing. Nothing in nature could supply its 
place. No matter how finely it is pulverized, it retains 
its dead-black color. The minutest particle is as black 
as the largest mass. It is insoluble in all liquids. It 
never decays. The paper may moulder ; we may even 
burn it ; and still, in the ashes, we can trace the form of 
the printed letter. The ancients used an ink composed 
of gum-water and lampblack, and manuscripts have been 
exhumed from the ruins of Pompeii and Herculaneum 
which are yet perfectly legible. 

A.nimat Cha7*coal, or bone-black, is made by burn- 
ing bones in close vessels. Mixed with H2SO4 it forms 
the basis of paste-blacking. It is largely used by sugar 
refiners (p. 190). Common vinegar filtered through it 
becomes the white vinegar of the pickle manufacturers. 



CARBON. 71 

Sl£i?ie?*al Coal. — This was formed at an early period 
of the world's history, called the Carboniferous Age. 
The earth was then pervaded by a genial, tropical climate. 
The air was denser and richer with vegetable food than 
now. The earth itself was a swamp, moist and hot, in 
which simple ferns towered into trunks a foot and a half 
in diameter ; and where plants like those which creep at our 
feet to-day, or are known only as rushes or grasses, grew 
to the height of lofty trees. The song of bird or hum of 
insect rarely echoed through the mighty fern-forests; 
but a strange and grotesque vegetation flourished with 
more than tropical luxuriance. In these swamps accu- 
mulated a vast deposit of leaves and fallen trunks which, 
under the water, gradually changed to charcoal. In the 
process of time, the earth settled at various points, and 
floods poured in, bringing sand, pebbles, clay, and mud, 
filling up all the spaces between the trees that were stand- 
ing, and even the hollow trunks themselves. The pres- 
sure of this soil and the internal heat of the earth com- 
bined to expel the gases from the vegetable deposits, and 
convert them into mineral coal.* In time this section 
was elevated again, and another forest flourished, to be in 
its turn converted into coal. Each of these alternate ele- 
vations and depressions produced a layer of coal or of 
soil. In these beds of coal we now find the trunks of 
trees, the outlines of trailing vines, the stems and leaves 
of plants as perfectly preserved as in a herbarium, so that, 
to the botanist, the flora of the Carboniferous age is 
nearly as complete as that of our own. 

* Where this process was nearly complete, anthracite coal, and where only 
partially finished, bituminous coal, was formed. The greater the pressure, the 
harder and purer the carbon produced ; unless, however, the covering was not 
sufficiently porous to allow the gases to escape, when bituminous coal was the 
result. 



72 INORGANIC CHEMISTRY. 

Coke is the refuse of gas-works, obtained by distilling 
the water, tar, and volatile gases from bituminous coal. 
It is burned in locomotives, blast-furnaces, etc. 

"Peat is an accumulation of half decomposed vegetable 
matter in swampy places.* It is produced mainly by a 
kind of moss which gradually dies below as it grows 
above, and thus forms beds of great thickness. Some- 
times, however, plants may grow in the form of a turf, 
and decay, thus collecting a vast amount of vegetable 
debris. This gradually undergoes a change, and becomes 
a brownish black substance, loose and friable in its text- 
ure, resembling coal, but, unlike it, containing 20 to 30 
per cent, of 0. Peat is used in large quantities as a fuel. 
For this purpose it is cut out in square blocks and dried 
in the sun. In some beds it is first finely pulverized, 
then pressed into a very compact form like brick. 

Mucfc is an impure kind of peat, not so fully carbon- 
ized ; though the term is frequently applied to any black 
swampy soil which contains a large quantity of decaying 
vegetable matter. Like charcoal, it absorbs moisture and 
gases, and is therefore used as a fertilizer. 

Various J^orms and Uses of Carbon. — We 
have seen in what contrary forms C presents itself. It is 
soft enough for the pencil-sketch, and hard enough for 
the glazier's use. Black and opaque, it expresses thought 
on the printed page : clear and brilliant, it gleams and 
flashes in the diadem of a king. In lampblack, it fre- 
quently takes fire spontaneously ; in graphite, it resists 
the heat of the fiercest flame ; in the diamond, it is an 



* These peat-beds are of vast extent. One-tenth of Ireland is covered by 
them. A bed near the mouth of the River Loire, is said to be fifty leagues in 
circumference. 



CARBON. 73 

insulator ; while in charcoal, it is so perfect a conductor 
of electricity that it is packed about the foot of lightning- 
rods to complete the connection with the earth. We 
burn it in our lamps, and it gives us light ; Ave burn it in 
our stoves, and it gives us heat ; we burn it in our en- 
gines, and it gives us power ; we burn it in our bodies, 
and it gives us strength. As fuel, it readily unites with 
0, yet we spread it as stove-polish on our iron-ware to 
keep the metal from rusting. It gives firmness to the 
tree and consistency to our flesh. It is the valuable ele- 
ment of all fuel, burning oils, and gases. Thus it sup- 
plies our wants in the most diverse manner, illustrating 
in every phase the forethought of that Being who fitted 
up this world as a home for His children. Infinite Wis- 
dom alone would have stored up such supplies of fuel 
and light, and hidden them far under the earth away 
from all danger of accidental combustion, or anticipated 
the requirements alike of luxury and the arts. 

Compounds.— Carbonic Anhydride , C0 2 . — 
Source. — This gas is commonly known as Carbonic 
Acid. It is found combined with Ca, in a large class of 
salts, known as the carbonates, viz., limestone, marble, 
chalk, etc., forming nearly one-half of their weight, and 
almost one-seventH of the crust of the earth. It comprises 
to,7joo P^ the atmosphere. It is produced throughout 
nature in immense quantities. Wherever C burns, in 
fires, lights, decay, fermentation, volcanoes — in a word, 
in all those various forms of combustion of which we 
spoke under the subject of 0, where that gas unites with 
C, C0 2 is the result. Each adult exhales daily about 8£ 
oz. of carbon changed to this invisible gas. Each bushel 
of charcoal, in burning, produces not far from 2500 gal- 



n 



INOR GANIC CHEMISTR T. 



Ions. A lighted candle gives off about 4 gallons pel 
hour.* 

Preparation. — For experimental purposes it is pre- 
pared by pouring. hydrochloric (muriatic) acid on marble 
or chalk. The reaction may be represented as follows : 



CaCO 



2HC1 




C0 2 + CaCl 2 + H 2 

Fig. 2k. 




Preparing C0 2 .t 

The C0 2 is liberated rapidly and may be gathered by 
displacing the air (see Fig. 24), while the calcium chlo- 
ride remains dissolved in the water of the flask. 

* Burn a piece of charcoal or a candle in a jar of O. Pour in a little lime- 
water and shake it well, when there will he a precipitation of chalk (calcium 
carbonate). Hold a jar of air over a "burning lamp or jet of coal-gas, or "breathe 
into the jar and apply the test. 

t Twist a wire around the neck of a small, wide-mouthed vial, to serve as a 
bucket. Dip the C0 2 with it ujoward from the jar and test with a lighted match. 
Dip the H (Fig. 14) downward., and test in same way. This illustrates in a strik- 
ing manner the difference between the gases in respect to specific gravity and 
combustion. 



C AR B iV. 



76 



The lest of C0 2 is clear lime-water. If we expose a 
saucer of lime-water to the air, the surface of the solu- 
tion will soon be covered with a thin pellicle of calcium 
carbonate (carbonate of lime), thus showing that there is 
C0 2 in the atmosphere; or if we breathe by means of a 
tube through lime-water, the solution will become turbid 
and milky, thus proving the presence of C0 2 in our 
breath : by breathing through the liquid a little longer it • 
will become clear, as the carbonate will dissolve in an ex- 
cess of C0 2 . 

Properties. — C0 2 is a colorless, odorless, transparent 
gas. with a slightly acid taste, and is a non-supporter of 

Fig. 25, 




Pouring C0 2 down an inclined plane. 



combustion. On account of its being heavier than air 
many amusing experiments can be performed with it. It 



76 



INOR GAKIC CHE MISTR Y. 



will run down an inclined plane, can be poured from one 
dish to another, drawn off by a syphon, dipped up with a 
bucket like water, or weighed in a pair of scales like 
lead. 

Fig. 26. 




CO. with a pair of scales 



To show the C in C0 2 hold a strip of Mg foil in a 
flame until well ignited, then insert in a jar of the gas. 
White flakes of magnesium oxide* (MgO) mixed with 
black particles of charcoal will be deposited. 

Asphyxia. — C0 2 accumulates in old wells and cel- 
lars, where it has cost the lives of many incautious 
persons. f The test of lowering a lighted candle should 
always be employed. If that be extinguished, your 
life would be in danger of "going out" in the same 
way, should you descend. The gas may be dipped out 
like water, or the well may be purified by lowering pans 
of slacked lime, or lighted coals which, when cool, will 
absorb the noxious gas. The coals may be re-ignited, and 



* These may "be dissolved by dilute HN0 3 , and the black C made more dis- 
tinct. 

t " Three or four per cent, of C0 2 in the air acts as a narcotic poison by pre* 
venting the proper action of the air upon the blood.' 1 '— Miller. 



C A R B iV. 



7? 




lowered repeatedly until the result is M &- 

reached.* Persons have been suffocated 
by burning charcoal in an open furnace 
in a closed room.f In France, it is not 
unusual to commit suicide in this manner. 
The antidote is to bring the sufferer into 
the fresh air, and dash cold water upon 
his face. In the celebrated Grotto del 
Cane, near Naples, the gas accumulates 
upon the floor, so that a man living near Pounn Q co 2 on a 
amuses visitors, for a small fee, by lead- 
ing his dog into the cave. He experiences no ill effects 
himself, but the dog falls senseless. On being drawn into 
the open air, the animal soon revives, and is ready to pick 
up his bit of black bread and enjoy the reward of his 
scientific experiment. 

C0 2 in Mines . — Miners call C0 2 choke-damp. It is 
produced by the combustion of fire-damp (see p. 81), 
which accumulates in deep mines, J and when mixed with 
air, burns like gunpowder, forming dense volumes of C0 2 , 
which instantly destroys the lives of all wiio may have 
escaped the flames of the explosion. § C0 2 has been used 

* A well, in which a candle would not burn within twenty- six feet of the bot- 
tom, was thus purified in a single afternoon. 

t The fumes of burning charcoal owe their deadly property largely to the pres* 
ence of CO (page 81), one per cent, of which in the air causes headache. 

\ The word gas was first used in the seventeenth century. Explosions, strange 
noises, and lurid flames had been seen in mine?, caves, etc. The alchemists, 
whose earthen vessels often exploded with terrific violence, commenced their 
experiments with prayer, and placed on their crucibles the sign of the cross- 
hence the name crucible from crux (gen. cruets), a cross. All these manifesta- 
tions were supposed to be the work of invisible spirits, to whom the name 
gcist or geisU a ghost or spirit, was applied. The miners were in special dan- 
ger from these unseen adversaries, and it is said that their church service con- 
tained the petition. " From spirits, good Lord, deliver us I" The names " spirits 
of wine," " spirits of nitre." etc., are a relic of the superstitions of that time. 

§ Where CO a alone is found, it is not considered as dangerous as the fire-cl a mp, 



78 INORGANIC CHEMISTRY. 

for the purpose of extinguishing fires in coal-mines. A 
mine near Sterling, England, had burned for thirty years, 
consuming a seam of coal nine feet thick, over an area of 
twenty-six acres. C0 2 , eight million cubic feet of which 
were required, was poftred into the mine, in a continuous 
stream, day and night, for three weeks. The mine was 
then cooled witji water, and within a month from the 
commencement of the operation was ready for the resump- 
tion of work. 

Abso?*plio?i of C0 2 by Z/iquids. — Water dis- 
solves its own volume of C0 2 under the ordinary pressure 
of the atmosphere, forming a solution of carbonic acid ; 
CO 2 + H 2 becoming H 2 C0 3 . With increased pressure a 
much greater amount will be absorbed. " Soda water " 
contains no soda, but is simply H 2 saturated with C0 2 
in a copper receiver strong enough to resist the pressure 
of 10 or 12 atmospheres. The gas gives the H 2 a 
pleasant, pungent, slightly acid taste, and by its escape, 
when exposed to the air, produces a brisk effervescence.* 
In beer, ginger-pop, cider, wine, etc., the C0 2 is produced 
by fermentation, f The gas escapes rapidly through cider 
and wine, and so produces only a sparkling ; while in 
a thick, viscid liquid, like beer, the bubbles are partly 
confined, and hence cause it to foam and froth. In 
canned fruits, catsup, etc., the " souring " of the vegeta- 

since it will not burn, and it is said that miners will even venture " where the 
air is so foul that the candles go out, and are then re-lighted from the coal on 
the wick by swinging them quickly through the air, when they burn a little 
while and then go out, and are re-lighted in the same way." 

* Pass a current of C0 2 through a gill of water. Add a few drops of blue lit- 
mus-solution. It will immediately redden. Boil the water, when the gas will 
escape and the water become blue. 

t Dissolve an oz. of sugar in 10 times its weight of water. Put it in a flask 
like that shown in Fig. 24, and add a little fresh brewer's yeast. If kept warm, 
in a short time it will give off CO 2 , which may be tested. 



CARBON. 79 

bles produces C0 2 , which sometimes drives out the cork 
or bursts the bottles with a loud report. 

.Liquid C0 2 . — By a pressure of 36 atmospheres, at 
a temperature of 32°, C0 2 becomes a colorless liquid, very 
much like H 2 0. When this is exposed to the air it evap- 
orates so rapidly that a portion is frozen into a snowy 
solid which burns the flesh like red-hot iron. By means 
of solid C0 2 , Hg can be readily frozen. When mixed 
with ether, and evaporated under the exhausted receiver 
of an air-pump, a cold of — 148° may be produced. (See 
Physics, p. 191.) 

y*enlilalion . — The relation of C0 2 to life is most 
important, and cannot be too often dwelt upon. We ex- 
hale constantly this dangerous gas, and if fresh air is not 
furnished continuously we are forced to rebreathe that 
which our lungs have just expelled.* The languor and 
sleepiness we feel in a crowded assembly, are the natural 
effects of the vitiated atmosphere, f The idea of drinking 
in at every breath the exhalations that load the air of a 
crowded, promiscuous assembly-room, is a most disgust- 
ing one. We shun impurity in every form ; we dislike 
to wear the clothes of another, or to eat from the same 
dish; we shrink from contact with the filthy, and yet 
sitting in the same room inhale their polluted breath. 
Health and cleanliness alike require that we should care- 



* It is a fact, as poetical as it is characteristic, that when the air comes forth 
from the lungs it is charged with the seeds of disease ; yet, as it passes out, 
it produces all the tones of the human voice, all songs, and prayers, and social 
converse. Thus the gross and deadly is by a divine simplicity made refined and 
spiritual, and caused to minister to our highest happiness and welfare. 

t It should be noted that the deleterious effects of ill-ventilation arise not only 
from the presence of C0 2 , but from the organic particles given off in the breath 
and exhaled from the skin. (See Physiology, page 93.) Rebreathed air is a fruit- 
ful source of consumption and scrofula. 



80 



IN OR GANIC CHEMISTRY, 



fully ventilate public buildings, school-rooms, and sleep- 
ing apartments.* 




A 



Testing the currents of air to and from fame. 

Ca?*bonic Oxide, CO, is a colorless, almost odorless 
gas, and has never been liquefied. It burns with a pale 
blue flame, absorbing an atom of from the air, and be- 



* Two openings are necessary to ventilate a room. To illustrate this, set a 
lighted candle in a plate of water, as shown in Fig. 28. Cover it with an open 
jar, over the neck of which is placed a common lamp-chimney. The light will 
soon be extinguished on account of the consumption of O, and the formation of 
C0 2 . Raise the jar at one side a trifle above the water, and the candle, if re- 
lighted, will burn steadily— fresh air coming in below, and the refuse passing off 
at the top. Replace the jar, and as the candle is flickering, insert in the chimney 
a slip of card, thus dividing the passage, when the light will brighten again. 
Hold a bit of smouldering touch-paper (page 45) at the top, and the smoke will 
show two opposite currents of air established in the chimney. Mines have been 
ventilated in this way by dividing the shaft. More commonly, however, they 
have two shafts at a little distance apart. 



C A RB OJY. 



81 



coming C0 2 . It is seen burning thus in our coal- 
stoves, and at the tops of tall furnace-chimneys. It is 
often formed abundantly on account of the action of 
heated carbon on C0 2 . When air enters at the bottom 
of a clear fire, C0 2 is formed at once ; but this gas pass- 
ing through the hot embers takes up a further quantity 
of C, becoming changed into CO:* C + 002 = 200, the 
volume of the gas being exactly doubled in bulk 
thereby. CO is a deadly poison, and escaping from 
coal-fires in a close room has often produced death. 
Both CO and C0 2 leak through the pores of cast Fe 
when heated, and still further injure the air of our 
houses and necessitate ventilation. The offensive odor 
which comes out on opening the door of our coal-stoves 
is caused by the compounds of S mixed with the CO. 

Marsh Gas. — Light Carburetted Hydrogen, CH 4 
(see p. 200). — This we have already spoken of under 
C0 2 , as the dreaded fire-damp of miners. It is colorless, 
tasteless, odorless, and 
burns with a yellowish 
flame. It is formed in 
swamps and low marshy 
places by the decomposi- 
tion of vegetable matter, 
and on stirring the mud 
beneath will be seen bub- 
bling up through the 
water. It may be collect- 
ed in the manner shown 



Fig. 29. 




Collecting Marsh-gas. 



* This fact is of great importance, since thereby much heat is wasted. Stoves 
are sometimes so constructed as to admit fresh air just above the grate, thus 
consuming this gas. 



82 



INOE G ANIC CHEMISTR Y. 



Fig. BO. 




in Fig. 29. It rises from 
the earth in great quanti- 
ties at many places. At 
Fredonia, N. Y., it is used 
in lighting the village. At 
Kanawha, Va., it was until 
lately employed as fuel for 
evaporating the brine in 
the manufacture of salt, 
In the oil-wells of Penn- 
sylvania, it frequently 
bursts forth with explosive 
violence, throwing the oil 
high into the air. 

Otefia?it Gas.— 
Heavy Carburetted Hy- 
drogen, C 2 H 4 . — This is 
a colorless gas, with a 
sweet, pleasant odor, and 
burns with a clear white 
light.* It may be easily 
prepared by heating in a 
large retort a mixture of 
one part of alcohol with 
two of H 2 S0 4 . 

Coal Gas is a very 
variable mixture. The 



* Fill a tall jar one-third full of 
defiant gas, and the remainder with 
chlorine gas. On lighting, the mix- 
ture will burn with a dense cloud of 
smoke. HC1 is the product of the 
combustion. 



Manufacture of Coal-gas. 



CARBON. 83 

proportion of olefiant gas and hydrocarbons having a 
similar composition gives whiteness to the flame ; while 
the H and CH 4 have little illuminating power, and serve 
mainly as carriers of the more valuable gases (Miller). 
Bituminous coal is heated in large iron retorts, B, until 
only coke is left and the volatile constituents are driven 
off. Among them are coal-tar, H 3 N, C0 2 > CO, N, com- 
pounds of S, ChL, and C 2 H 4 .* This mixture is led 
through the curved pipes, d, beneath the H 2 in the hy- 
draulic main,F; along the tube, g, to the tar cistern ; 
thence up and down the condenser, j. On the way it be- 
comes cooled and loses its coal-tar, ammoniacal salts, f 
and liquid hydrocarbons. Lastly it is passed over lime, 
Lm, which absorbs the C0 2 and the H 2 S.J The remain- 
ing gases form the mixture we call " gas." This is col- 
lected in the gasometer, P, the weight of which forces it 
through all the little gas-pipes, and up to every jet in the 
city. 

Coal-gas is very poisonous, and even in small quantities 
exceedingly deleterious. When mixed with air it ex- 
plodes with great violence. Its unpleasant odor, though 
often annoying, is a great protection, as we are thereby 
warned of its presence. 

Cyanogen,^ Cy=CN. — Preparation.— As N and C 

* None of these substances exists in coal. They are formed by the action of 
heat, which causes the H, C, O, N and S to combine and make a multiplicity of 
compounds. 

tThe H 3 N is neutralized by HC1, thus forming chloride of ammonium (sal- 
ammoniac, H 4 N,C1). On evaporation, the tough, fibrous crystals of the salt are 
obtained. (See page 135.) 

X The removal of the sulphur compounds is especially important, since, when 
burned, they furnish sulphurous and sulphuric acids, which are very injurious to 
books, paintings, and furniture. 

§ The term cyanogen means " blue producer ;" this gas being the character- 
istic constituent of Prussian blue. 



84 INORGANIC CHEMISTRY. 

do not combine directly, this gas is obtained in an in- 
direct way. Mix the parings of horns, hides, etc., with 
pearlash (potassium carbonate) and iron filings, and heat 
in a close vessel. The N and C of the animal substances, 
in their nascent state, will combine, forming Cy ; this 
uniting with the Fe and K will produce the beautiful yel- 
low crystals of potassium ferro-cyanide (yellow prussiate 
of potash). From this salt the mercury cyanide is made, 
which when heated decomposes into Hg and Cy. 

Properties. — Cy is a transparent, colorless gas, with a 
penetrating odor. It burns with a characteristic rose- 
edged purple flame, and is exceedingly poisonous. It is 
very interesting from the fact that, though a compound, 
it unites directly with the metals like the elements I, B, 
etc. It is therefore called a compoimd radical (root). 
We shall find this subject of great importance in Organic 
Chemistry. 

IPyd?*ocyanic Acid, HCy. — Prussic acid, as it is 
commonly called, is a fearful poison. A single drop on 
the tongue of a large dog is said to produce instant death. 
H 3 N, cautiously inhaled, is its antidote. Its bitter flavor 
is detected in peach blossoms, the kernels of plums or 
peaches, bitter almonds, and the leaves of wild cherry. 

ITutminic A.cid (fulmen, a thunderbolt). — This 
compound of Cy is known only as combined with the va- 
rious metals forming fulminates, which are remarkably 
explosive. Fulminating mercury was used to fill the 
bombs with which the life of Napoleon III. was attempt- 
ed in 1858. It is employed in making gun-caps. A drop 
of gum is first put in the bottom of the cap, over which 
is sprinkled a little fulminating mercury, and this is 



CARBON. 85 

sometimes covered with varnish to protect it from any 
moisture. 



COMBUSTION, 



Combustion, in general, is the rapid union of a sub- 
stance with 0, and is accompanied by heat and light.* 

The Ig?iili?ig (Poi?il of any substance is the tem- 
perature at which "it catches fire." We elevate the 
heat of a small portion to the point of rapid union with 
0, and that part in burning will give off heat enough to 
support the combustion of the rest. — Example : In mak- 
ing a fire, we take paper or shavings, which being poor 
conductors of heat, and exposing a large surface to the 
action of 0, are easily raised to the required temperature. 
Having thus obtained sufficient heat to start the combus- 
tion of chips or pine sticks, we gradually increase it until 
there is enough to ignite the coal or wood. 

Chemistry of a Fire. — Our fuel and lights, such 
as wood, coal, oil, tallow, etc., consist mainly of C and 
H, and are, therefore, called hydrocarbons. In burn- 
ing they unite with the of the air, forming H 2 
and C0 2 . These both pass off, the one as a vapor, the 
other as a gas. In along stove-pipe, the H 2 is some- 
times condensed, and drips down, bringing soot upon our 
carpets. Ashes comprise the mineral matter contained 
in the fuel, united with some of the C0 2 produced in the 
fire. When we first put fuel in the stove, the H is liber- 
ated with some C, in the form of marsh or olefiant gas. 

* There are forms of combustion known to the chemist which are not oxida- 
tion ; as the union of S and Cu. (See page 97, note.) 



86 



INORGANIC CHEM1STR Y. 



This burns with a flame. Then, the volatile H haying 
passed off., we haye left the C, which burns as coal 
merely. In maple there is much more C than in pine, so 
it forms a good " bed of coals." In the burning of fuel 
there is no annihilation; but the H 2 0, C0 2 , and the 
ashes, weigh as much as the wood and the that com- 
bined with it. JSTo matter how rapidly the fire burns, 
eyen in the blaze of the fiercest conflagration, the ele- 
ments unite in exact atomic weights. 

C is most wisely fitted for fuel, since the product of 
its combustion is a gas. Were it a solid, our fires would 
be choked, and before each supply of fresh fuel we 
should be compelled to remoye the ashes. In the case 
of a candle or lamp it would be still more annoying, 
as the solid product would fall around our rooms. 
Still another useful property is the infusi- 
bility of C. Did C melt like Z or Pb on the 
application of heat, how quickly in a hot fire 
would the coal and wood run down through 
the grate and out upon the floor in a liquid 
mass ! 

Cliei?iistry of a Ca?idle. — Flame is 
burning gas. A candle is a small " gas-work," 
and its flame is the same as that of a " gas- 
burner." First, we haye a little cupful of tal- 
low melted by the heat of the fire aboye. The 
ascending currents of cool air which supply 
the light with also keep the sides of the cup 
hard, unless the wind blows the flame down- 
ward, when the banks break, there is a crevasse, and our 
" candle runs down." Next, the melted tallow is carried 
by capillary attraction up the small tubes of the wick into 



Fig. 31. 




Form of 
Jlame. 



C OMB US T I N. 



87 



Fig. 32. 



the flame. There it is turned into gas by the heat, 
Flame is always hollow, and at the center, near the wick, 
is the gas just formed. If a match be placed across a 
light, it Avill burn off at each side, in the ring of the 
flame, while the center will be unblackened.* The 
gas may be conducted out of the flame by a small 
pipe, and burned at a little distance from the can- 
dle. Flame is hollow because there is no 
at the center. The gas floats outward 
from the wick. It comes in contact with 
the of the air, and the H, requiring 
least heat to unite, burns first, forming 
H 2 0. This produces heat enough to 
make the tiny particles of C, floating 
around in the flame of burning H, white- 
hot, f They each send out a delicate 
wave of light, and passing on to the 
outer part, where there is more 0, burn, 
forming C0 2 . The flame is blue at the 
bottom, because there is so much at 
that point that the H and burn to- 
gether, and so give little light. The H 2 
may be condensed on any cold surface. 
The CQ 2 niay be tested by passing the invisible vapor of 
a candle through lime-water. The wick of a candle does 
not burn because of the lack of at the center. It, how- 




Match in flame; the 
S and P being un- 
consumed. 



* Take a sheet of white paper and thrust it quickly down upon the flame of a 
candle or lamp. It will burn in a ring, and when the paper is removed the cen- 
ter will be found unblackened. 

t Frankland has shown that the intensity of a flame, in general, is determined 
by the density of the gas : thus a jet of H burning under a pressure of ten 
atmospheres will furnish sufficient light to read a newspaper at a distance of 
two feet. 



88 



1N0R OANIC CHEMISTR F. 



ever, is charred, as all the volatile gas is driven off by the 
heat. If a portion falls over to the outer part, where 



Fig. 88. 




Testing the CO 2 of aflame by drawing the gas through lime-water. 



there is 0, it burns as a coal. If we blow out a candle 
quickly, the gas still passes off, and we can relight 
it with an ignited match held at some distance from 
the wick. The tapering form of the flame is due to the 
currents of air that sweep up from all sides toward it. 
The candle must be snuffed, because the long wick would 
cool the blaze below the igniting point of C and 0, and 
the C would pass off unconsumed. A draught of air, or 
any cold substance thrust into the flame, produces the 
same result, and deposits the C as soot. Plaited wicks 
are sometimes used, which, being thin, fall over to the 
outside and burn, requiring no snuffing. 

Cliemisiry of a Z,amp. — A chimney confines the 
hot air, and makes a draught of heated to feed the 



COMB U S T 10 N. 



89 




Fig. 35. 



flame. A flat wick is used, as it Fi 9- ^ 

presents more surface to the ac- 
tion of the 0. Argand lamps 
have a hollow wick which admits 
into the center of the blaze. 
The film which gathers on a chim- 
ney when we first light a lamp, 
is the H 2 produced in the flame, 
condensed on the cold glass. A 

° H a condensed f ram aflame. 

pint of oil forms a full pint of 

H 2 0. Spirits of turpentine, tar, pine-wood, etc., con- 
tain an excess of C, and not enough H to heat it to 
the igniting point. These, there- 
fore, produce clouds of soot. Alco- 
hol contains an excess of H and little 
C, hence it gives off great heat and 
little light. 

jDary' s Safety £a?7ip, used 
by miners, consists of an ordinary 
oil-lamp, surrounded by a cylinder 
of fine wire-gauze. When it is car- 
ried into an atmosphere containing 
the dreaded fire-damp, the flame en- 
larges and becomes pale, and when 
the quantity increases, the gas will 
quietly burn on the inside of the 
cylinder.* There is no danger of 
an explosion so long as the gauze 




Davy's Safety Lamp. 



* Tlie principle of the lamp can be illustrated by holding a fine wire-gauze 
over the flame of a candle or lamp (Tig. 36). The flame will not pass through, 
since the wire will conduct away the heat and so reduce the temperature below 
the igniting point. A jet of gas, issuing at a low temperature, may be lighted 
on either side of the gauze at pleasure. 



90 



INOR GANIC CHEMISTR Y. 




Wire gauze over flame. 



remains perfect,* Through carelessness, however, fearful 
m 3g accidents have occurred. Miners become 

extremely negligent, and an account is 
given of an explosion, in which about a 
hundred persons were killed, caused by 
a lamp being hung on a nail by a hole 
broken through the wire-gauze. 

Sunsen's Burner is used in the 
laboratory. It consists of a jet of gas, a, 

surrounded by a metal tube, c, at the bottom of which are 

openings, 5, for the admission of air. The gas passes up 

the tube, mingles with 

the air, and burns 

at the top without 

smoke. The is 

supplied in sufficient 

quantity to burn the 

H and C simultane- 
ously ; hence there is 

great heat with little 

light and no smoke. 
The Oxy-hydro- 

gen Slow-pipe is 

so constructed that 

a jet of is intro- 
duced into the center 

of one of burning H, 

thus producing a solid 

flame. A watch-spring will burn in it with a shower of 

* At such a time, however, the wise miner will leave the place of danger, lest 
the metal should melt and the fire escape to the gas, when an explosion would 
ensue. 




Humeri's burner. 



COMB US TI N. 



91 



sparks. Pt, the most infusible of metals, will readily 
melt. In the common flame, as we have seen, the little 

Fig. 38. 




The Oxy~hydrogen Blow-pijie. 

particles of solid C, heated by the burning H, produce 
the light. As there is no solid body in the blow-pipe 
flame, it is scarcely luminous. If, however, we insert in 
it a bit of CaO, or MgO, a dazzling light is produced. 
This is called the " Drummond," "Lime," or " Calcium" 



INOR GANIC CHEMISTR F. 



Fig. 39. 



a 

F 



Light, and with a properly arranged reflector has been 
seen at a distance of one hundred and eight miles in 
broad sunlight. 

Mouth !Blow-pipe. — In the com- 
mon blow-pipe, used by jewelers and 
mineralogists, a current of air from the 
lungs is thrown across the light just 
above the wick. The flame loses its 
brilliancy and is driven one side in the 
form of a cone (Fig. 40). Three parts 
are clearly visible. In the center is a 
blue cone ending at a ; outside of this 
is a whiter and more luminous one ter- 
minating at h ; and beyond this a pale 
yellow flame, c. The blue cone is 
caused by the excess of from the 
blow-pipe burning the C and H at the 
same time. The luminous cone con- 
tains C in excess, which being heated 
gives out light. The combustible vapor 
at this point, hot and ready to com- 
bine, will take from any substance exposed to it, and 
is therefore called the reducing flame. The outer en- 




Common Blow -pipe. 



Fig. k0. 




velope contains the thrown from the lungs, borne for- 
ward by the jet of flame, and highly heated by it. It will 



C0 3IBUSTI0N. 93 

unite with a metallic body, and is therefore called the 
oxidizing flame. — Example : Hold a copper cent in the 
blaze of an alcohol lamp ; in the " reducing flame " its 
rust, copper oxide, will be cleaned off, and the metal will 
shine as brightly as if just from the mint. In the "oxi- 
dizing flame " a film of copper oxide will be formed over 
the surface, and as we move the cent the most beautiful 
play of colors will flash from side to side.* 

J?xti?iguis?iing Fires. — Blowing on a candle or 
lamp extinguishes it, because it lowers the heat of the 
flame below the igniting point of the gases, f Fires are 
put out by H 2 partly for the same reason, and also be- 
cause it envelops the wood and shuts off the air. If a 
person's clothes take fire, the best course is to wrap him 
in a blanket, carpet, coat, or even in his own garments. 
This smothers the fire by shutting out the 0. Great care 
should be taken in a fire not to open the doors or win- 
dows, so as to cause a draught of air. The entire build- 
ing may burst into a blaze, when the fire might have 
languished for want of 0, and so have been easily ex- 
tinguished. 

Sponla?ieotis Combustion. — Sometimes chemical 
changes take place in combustible substances, whereby 
heat enough is generated to cause ignition. CaO occa- 
sionally absorbs H 2 0, so as to set fire to wood in contact 
with it. Fresh-burned charcoal has the power of absorb- 
ing gases in its pores so rapidly as to become ignited. 

* Introduce a small piece of common flint-glass tube into the reducing flame. 
The glass will become opaque and black, because the Pb will be reduced from 
the transparent form of oxide to the opaque condition of metal. When this has 
happened, place the black portion just in front of the oxidizing flame. The dis- 
coloration will slowly disappear, and the Pb will recombine with O from the air 
and the glass again become transparent. 

t Sometimes, also, the flame is driven off by the mere force of the breath. 



94 INORGANIC CHEMISTRY. 

Heaps of coal take fire from the iron pyrites contained in 
them, which is decomposed by the moisture of the air. 
The waste cotton used in mills for wiping oil from 
the machinery, when thrown into large heaps, often ab- 
sorbs from the air so rapidly that it bursts into a blaze. 

PRACTICAL QUESTIONS. 

1. Why does not blowing cold air on a fire with a bellows ex- 
tinguish it ? 

2. Why will pine-wood ignite more easily than maple ? 

3. Why is fire-damp more dangerous than choke-damp ? 

4. Represent the reaction in making C0. 2 , showing the atomic 
weights, as in the preparation of on page 28. 

5. Should one take a light into a room where the gas is escap- 
ing? 

J 6. What causes the difference between a No. 1 and a No. 4 
pencil ? 

7. Why does it dull a knife to sharpen a pencil ? 

8. Why is slate found between seams of coal ? 

9. Why was the coal hidden in the earth ? 

10. Where was the C, now contained in the coal, before the Car- 
boniferous age ? 

11. Must the air have then contained more plant food ? (p. 98.) 

12. What is the principle of the aquarium? 

13. What test should be employed before going down into an old 
well or cellar ? 

14. What causes the sparkle of wine, and the foam of beer? 

1 5. What causes the cork to fly out of a catsup bottle ? 

16. What philosophical principle does the solidification of C0 2 
illustrate ? 

17. Why does the division in the chimney shown in Fig. 28 pro- 
duce opposite currents ? 

18. What causes the unpleasant odor of coal-gas ? Is it useful ? 

19. What causes the sparkling often seen in a gas-light ? 

20. Why does H in burning give out more heat than C ? 

21. Why does blowing on a fire kindle it, and on a lighted lamp 
extinguish it ? 

22. Why can we not ignite hard coal with a match 1 



C MB US T I X. 95 

23. What causes the dripping of a stove-pipe ? 

24. Why will an excess of coal put out a fire ? 

25. Why do not stones burn as well as wood ? 

26. Why does not hemlock make " a good bed of coals ? " 

27. What adaptation of chemical affinities is shown in a light ? 

28. Is there a gain or a loss of weight by combustion ? 

29. Why does snuffing a candle brighten the flame ? ' 

30. Why is the flame of a candle red or yellow, and that of a 
kerosene oil-lamp white ? 

31. Why is it beneficial to stir a wood-fire, but not one of anthra- 
cite coal ? 

32. Why will water put out a fire ? 

33. Wliat should we do if a person's clothes take fire ? 

34. Ought the doors of a burning house to be thrown open ? 

35. Why does a street gas-light burn blue on a windy night ? Is 
the light then as intense ? The heat ? 

36. Why does not the lime burn in a calcium-light ? 

37. Why is a candle-flame tapering ? 

38. Why does a draught of air cause a light to smoke ? 

39. What makes the coal at the end of a candle-wick? 

40. Which is the hottest part of a flame ? 

41. Why does not a candle-wick burn? 

42. How does a chimney enable us to burn without smoke highly 
carboniferous substances like oil ? 

43. How much C0 2 in 200 lbs. of chalk ? 

44. What weight of C0 2 in a ton of marble ? 

45. What is the difference between marble and chalk? (See 
page 139.) 

46. Why does not a cold saucer held over an alcohol flame blacken, 
as it does over a candle or gas-light ? 

47. Could a light be frozen out, i. e., extinguished, by merely low- 
ering the temperature ? 

48. How much C0 2 is formed in the combustion of one ton of C ? 

49. What weight of C is there in a ton of C0 2 ? 

50. How much is consumed in burning a ton of C ? 

51. What weight of sodium carbonate (Na 2 C0 3 , " carbonate of 
soda") would be required to evolve 12 lbs. of C0 2 ? 

52. How much C0 2 will be formed in the combustion of 30 grs. 
of CO? 

53. What weight of hydrogen sodium carbonate (HNaC0 3 , "bi- 
carbonate of soda ") would be required to evolve 12 lbs. of C0 2 ? 



96 INORGANIC CHEMISTRY. 

54. Write in double columns the different properties of carbonic 
anhydride and carbonic oxide ; thus, 

C0 2 is I CO is 

1, non-inflammable. I 1, inflammable.. 



THE ATMOSPHERE. 

The " air we breathe " consists of N, 0, C0 2? and watery 
vapor. The first composes i, the second I, the third 
about jo,1)oo> an( i the last a variable amount.* A very 
clear idea of the proportion of these several constituents 
may be formed by conceiving the air, not as now dense 
near the surface of the earth, and gradually becoming 
rarefied as we ascend to its extreme limit of perhaps 500 
miles, but of a density throughout equal to that which 
it now possesses near the earth. The atmosphere would 
then be about five miles high. The vapor would form a 
sheet of H 2 over the ground five inches deep, next to 
this the CO 2 a layer of 13 feet, then the a layer of one 
mile, and last of all the N one of four miles. — Gkaham. 
In this arrangement we have supposed the gases to 
be placed in the order of their specific gravity. The 
atmosphere is not thus composed in fact, the various 
gases being equally mingled throughout, in accordance 
with a principle called the " Law of the diffusion of 
Gases." If we throw a piece of lead into a brook, it will 
settle instantly to the bottom by the law of gravitation, 
and will remain there by the law of inertia. But if we 
throw into the atmosphere a quantity of C0 2 > it will 
sink for an instant, then immediately begin to mingle 

* The N and O form so large a part, that they are considered in ordinary cal- 
culation to compose the whole atmosphere. 



THE ATMOSPHERE. 



97 



Si 



ju 



with the surrounding air, and soon become dissipated. — 
Example : If we invert an open-mouthed bottle full of H 
over another full of C0 2? the H, light as it is, will 
sink down into the lower jar; and the C0 2 , F ^' hl '_ 
heavy as it is, will rise into the upper jar; 
and in a few hours the gases will be found 
equally mixed. By this law the proportion of 
the elements of the atmosphere is the same every- 
where, and has not varied within historic times. 
Samples have been analyzed from every conceiva- 
ble place, from polar and torrid regions, from 
prairies and mountain-tops, from balloons and 
mines, from crowded capitals and lonesome for- 
ests, and even from bottles found sealed up in the 
ruins of Herculaneum, and the result is almost 
exactly the same. These gases do not form a 
chemical compound, but a mere mechanical mix- 
ture,* and they are as distinct in the air as so many grains 
of wheat and corn mingled in a measure. 

Each of the constituents of the air has its separate use 
and mission. The action of and N we have already 
seen. 

Uses of C0 2 . — Carbonic acid bears the same relation 
to vegetable that does to animal life. The leaf — the 



x 



Diffu- 
sion of 
gases. 



* " To illustrate the difference between a mechanical mixture and a chemical 
compound, mix powdered S and filings of Cu. The color of the S as well as that 
of the Cu will disappear, and to the unaided eye will present a uniform greenish 
tint ; with the microscope, however, the particles of Cu may be seen lying by 
the side of those of S ; and we can wash away the lighter S with H 2 0, leaving 
the heavier Cu behind. Here no chemical action has occurred ; the S and Cu 
were only mechanically mixed. If we next gently heat some of the mixture it 
soon begins to glow, and on examining the mass we find that both the Cu and 
the S have disappeared as such, that they cannot be distinguished even with the 
most powerful microscope, and that in their place we have formed a black sub- 
stance possessing properties entirely different from those possessed either by the 
Cu or the S."— Roscoe. 



98 INORGANIC CHEMISTRY. 

plant-lungs — through its million of little stomata, 01 
mouths, drinks in the C0 2 . In that minute leaf -labora- 
tory, by the action of the sunbeam, the C0 2 is decom- 
posed,* the C being applied to build up the plant, and 
the returned to the air for our use. Plants breathe out 
as we breathe out C0 2 . We furnish vegetables with 
air for their use, and they in turn supply us. There is 
thus a mutual dependence between the animal and the 
vegetable world. Each relies upon the other. Deprived 
of plants we should soon exhaust the from the air, 
supply its place with C0 2? and die; while they, removed 
from us, would soon exhaust the CO 2 , and die as cer- 
tainly. We pollute the air while they purify it. Each 
tiny leaf and spire of grass is thus imbibing our foul 
breath, and returning it to us pure and fresh, f This in- 



* " In order to decompose carbonic acid in our laboratories, we are obliged to 
resort to the most powerful chemical agents, and to conduct the process in ves- 
sels composed of the most resisting materials, under all the violent manifesta- 
tions of light and heat, and we then succeed in liberating the carbon only by 
shutting up the oxygen in a still stronger prison ; but under the quiet influences 
of the sunbeam, and in that most delicate of all structures, a vegetable cell, the 
chains which unite together the two elements fall off, and, while the solid car- 
bon is retained to build up the organic structure, the oxygen is allowed to 
return to its home in the atmosphere. There is not in the whole range of chem- 
istry a process more wonderful than this. We return to it again and again, with 
ever increasing wonder and admiration, amazed at the apparent inefficiency of 
the means, and the. stupendous magnitude of the result. When standing be- 
fore a grand conflagration, witnessing the display of mighty energies there in 
action, and seeing the elements rushing into combination with a force which 
no human agency can withstand, does it seem as if any power could undo that 
work of destruction, and rebuild those beams and rafters which are disappear- 
ing in the flames ? Yet in a few years they will be rebuilt, This mighty force 
will be overcome ,• not, however, as we might expect, amidst the convulsion of 
nature, or the clashing of the elements, but silently, in a delicate leaf waving 
in the sunshine. ,, — Cooke. 

t From this statement it is evident that the foliage of house-plants must be 
healthful. Moreover, there is some reason to believe that the O which they ex- 
hale is highly ozonized, and therefore of great value in destroying miasmic 
germs. We should remember, however, that flowers exhale C0 2 ; and the odor 
of certain plants, and the pollen of others, are very injurious. Plants and 
flowers, which to one person are innocuous, are to another detrimental. Thus 



THE A Tiro SPHERE. 
Fig. !&. 



99 




Apparatus arranged to catch the O evolved from a sjrrig of leaves. 

terchange of office is so exactly balanced, that, as we have 
seen, the proportion of C0 2 and of 0, in the open air, 
never varies.* 



the fragrance of new-mown grass, which is so agreeable to some, produces in 
others what is termed the hay-fever ; due, it is said, to the pollen of the grass. 
Each family, therefore, must determine for itself what should be excluded from 
its collection. It is evident that flowerless plants, like the ivy, etc., are harm- 
less, while the cheerfulness given to an apartment by even a few pots of flowers 
on a window-bench, should induce one to take some trouble in order to make a 
selection which will not only beautify but purify the room. 

* "Two hundred million tons of coal are now annually burned, producing six 
hundred million tons of C0 2 . A century ago, hardly a fraction of that amount 
was burned, yet this enormous aggregate has not changed the proportion in the 
least. , '— Youmans . 

LofC. 



100 INORGANIC CHEMISTRY. 

^Pla?zts Store up Solar JForce. — The sunbeam, 
which is thus strong enough to wrench apart the C and 
0, sends out the full of potential force, and, by its 
energy, builds up the plant. The force of the sunbeam 
is then latent in the vegetable structure. The sun shin- 
ing on a meadow causes the grass to grow. If the hay- 
made from it be eaten by an animal, the same amount of 
force will be liberated as was received from the sun. A 
tree towers upward through a century of sunshine. When 
burned, it sets free as much force as was needed to per- 
fect its growth. A bushel of corn, then, represents not 
alone so much C, H, and 0, but also an amount of sun- 
force which is available for any purpose to which we wish 
to apply it. (See Conclusion.) 

Animals Spend Solar J? 1 o?*ce. — In the process of 
digestion the force stored in the plant is transferred to 
the animal, is given out by its muscles on their oxi- 
dation and produces motion, heat, etc. H 3 N, C0 2 , and 
H 2 are decomposed by the plant and organized into 
complex molecules (see p. 182), full of potential force. 
The animal oxidizes the organic molecules, and breaks 
them up into H 3 N, C0 2 , and H 2 again — simple mole- 
cules robbed of force which the animal has used. Thus 
the plant builds up and the animal tears down. The 
plant garners in the sunbeam and the animal scatters it 
again. The plant reduces and the animal oxidizes. 

Uses of Watery Vapor. — We have already seen the uses 
of H 2 0. As vapor, it is everywhere present and ready to 
supply the wants of animals and plants. Were the air 
perfectly dry, our flesh would become shriveled like a 
mummy's, and leaves would wither as in an African 
simoom. Eivers and streams flow to the ocean ; yet all 



THE ATMOSPHERE. 101 

their fountains are fed by the currents that move in the 
air above us. H 2 rises as vapor, flows on to colder 
regions, falls as rain, dew, snow, or hail, and then work- 
ing as it goes whatever it finds to do, moistening a plant 
or turning a water-wheel, wends its way back to the 
ocean. Thus Niagara itself must first rise to the clouds 
as vapor before it can fall as a cataract. 

/ Pe?*mane?ice of the Atmosphere. — The elements 
of the air unite to form HN0 3 only by the passage of elec- 
tricity, and then in minute quantities. If they combined 
more readily we should be constantly exposed to a shower 
of this corrosive acid that would be destructive to all 
vegetation, clothing., and even our bodies themselves. — 
0,* N, and C0 2 are reduced from their gaseous form 
only by an apparatus specially made for the purpose, 
and under circumstances which could rarely, if ever, 
occur in Nature. These substances are therefore con- 
stantly in the condition promptly to supply the demands 
of animals and plants. — Watery vapor, on the contrary, is 
deposited as dew or rain by the slightest change of tem- 
perature ; this readiness of condensation is equally neces- 
sary to meet the wants of animal and vegetable life. — 
The permanence of the air produces all the uniformity of 
sound. Were the proportions of the atmosphere to change, 
all "familiar voices" would become strange and uncouth, 
while the harmonies of music would shock us with unwont- 
ed discord, f Each element of the air is adapted to a special 
work, and all are fitted to the present order of nature. 

* The liquefaction of the so-called "permanent gases," N, O, H, etc., is the 
great chemical triumph of 1877. It was accomplished by Cailletet of Paris ana. 
Pictet of Geneva, almost simultaneously. 

'+ If, by some means, the air of a concert-room could be changed to H, for 
instance, the bass voices would become irresistibly comic and shrill, while the 
tenor would emulate railway whistles. 



102 



INORGANIC CHEMISTRY. 



THE HALOGENS. 



Chlorine . . Symbol, CI ; Atomic Weight, 35.5 ; Specific Gravity, 2.43 



Iodine 


u 


I; 


a 


r< 


127.; 


(i 


4,94 


Bromine.. 


a 


Br; 


u 


u 


80.; 


a 


(at 32°), 3.18 


Fluorine.. 


u 


F; 


it 


u 


19.: 


a 


1.31 



These four elements are closely allied, and form a class 
of compounds known as the halogens, from hals, salt, be- 
cause they resemble common salt (NaCl).* 

Chloeike is named from its green color. It is chiefly 
found in salt, of which it forms 60 per cent. It is pre- 

Fig. US. 




Preparing CI. 



* In comparing the halogens with one another, the chemical activity of F, 
which has the smallest atomic weight, is the most powerful : next in the order 
of activity is CI, then Br, and, lastly, I, the atomic weight increasing as the chem- 
ical energy declines. CI is gaseous, Br, liquid, and I solid. The specific gravity, 
the fusing point, and the boiling point, rise as the atomic weight increases. The 
halogens combine energetically with the metals, and, when united with the same 
metal, furnish compounds which are isomorphous ; that is to say, they all crys- 
tallize in the same form — potassium fluoride, chloride, bromide, and iodide, for 
example, all crystallize in cubes. Each, also, forms with H a soluble, powerful 
acid-HCl, HI,*HBr, HF. 



THE HALOGENS. 



103 



pared by heating NaCl with Mn0 2 , H 2 S0 4 , and H 2 0.* 
This mixture liberates the gas in great quantities. CI is 
heavier than common air, and hence may be collected by 
displacement, as in the preparation of C0 2 > or a solution 
of the gas may be obtained by using the apparatus shown 
in Fig. 43, while the excess is gathered in a receiver. 

Properties. — CI has a greenish-yellow color, and a pecu- 
liarly disagreeable odor. It produces a suffocating cough, 
which can be relieved by breathing ammonia or ether. 
Arsenic, Dutch gold-leaf, phosphorus, etc., com- 
bine with it so rapidly as to inflame. Powdered 
antimony slowly dropped into it produces a 
shower of brilliant sparks. Cold water absorbs 
about twice its volume of the gas, which, in 
the sunlight, turns to hydrochloric acid (HC1). 
CI has such a powerful affinity for H, that it 
will even attract it out of a moist organic body, 
and form HC1. It acts thus upon turpentine, TurpenMne 
depositing its C in great flakes of soot. It dis- in ol 
charges the color of indigo, ink, wine, etc., almost in- 
stantaneously. It has no effect on printers' ink, the col- 
oring matter of which contains no H. (See p. 222.) 

Uses. — ^Bleaching . — In domestic bleaching the 
cloth is first boiled with strong soap, to dissolve the 
grease and wax, and then laid upon the grass, being fre- 
quently wet to hasten the action of the air and sun. The 
dew seems to have a peculiar influence, while the corro- 
sive ozone of the atmosphere doubtless aids in the pro- 
cess. The H of the coloring matter unites with the of 




* The chemical reaction is as follows : 

Manganese Sodium Sulphuric Manganese Hydrogen Sodi- w +<«. nM™™ 
Dioxide Chloride Acid Sulphate urn Sulphate Water chlonne 

MnO a + 2NaCl + 3H 2 S0 4 = MnS0 4 + 2HNaSQ 4 + 2H 2 + Cl a . 



104 INORGANIC CHEMISTRY. 

the air or dew, forming H 2 0, and destroying the coloring 
compound.* 

The method of bleaching on a large scale is as follows : 
The cloth is well washed, and boiled in water with strong 
alkalies, to remove the grease, etc.; next it is passed 
through a solution of chloride of lime, and lastly through 
diluted H 2 S0 4 . In this step the acid unites with the 
lime, and sets free the CI, which in turn combines with 
the H of the coloring matter, forming HC1, and thus 
bleaches the cloth. "About twenty-four hours are re- 
quired for this process, and the cost is not quite a cent 
per yard." Paper-rags are bleached in the same way in 
paper-mills, f 

^Disinfectant. — CI is a powerful disinfectant. It 
breaks up the offensive substance by uniting with its H, 
as in bleaching. Other disinfectants, as burnt paper, 
sugar, etc., only disguise the ill odor by substituting a 
stronger one. In the sick-room CI is set free from chlo- 
ride of lime (bleaching powder) by exposing it to the air 
in a saucer with a little H 2 0. The gas soon passes off, 
though the process may be hastened by adding a few 
drops of dilute acid. Chloride of lime is, therefore, of 



* This was essentially the process long pursued in Holland, where linens were 
formerly carried for bleaching; hence the term "Holland linen," still in use. 
The H 2 about Haarlem was thought to have peculiar properties, and no other 
could compete with it. Cloths sent there were kept the entire summer, and were 
returned in the fall. Later a similar plan was adopted in England. But the vast 
extent of grass-land required, the time occupied, and the temptation to theft, 
made the process extremely tedious and expensive. The statute laws of that 
time abound in penalties for cloth stealing. It is estimated that all the men, 
women, and children in the world could not, by the old way, bleach all the cloth 
that is now used. • 

t Stains can be removed from uncolored cloth by " Labarraque's Solution," a 
compound of CI, which can be obtained of any druggist. Place the cloth in this 
liquid, and if the stain is obstinate, pour on a little boiling H 2 0, or place it in 
the sun for some hours. Then rinse thoroughly in cold H 2 0, and dry. 



THE HALOGENS. 



105 



great service for disinfecting all places exposed to any 
noxious or unpleasant effluvia. Hospitals and rooms in 
which persons have died of a contagious disease are puri- 
fied by placing in them pans full of a mixture which is 
disengaging CI in large quantities. 

Compounds. — Hy droc?iloric Acid, Muriatic 
Acid, H CI. — When CI and H 
are mixed in the dark and ex- 
posed to the direct sunlight they 
unite with an explosion. In the 
arts HC1 is prepared from H 2 S0 4 
and NaCl. The reaction is as 
follows: NaCl + H 2 S0 4 =HCl + 
HNaS0 4 . 

Properties. — It is an irrespira- 
ble, irritating, acid gas, with an 
intense attraction for H 2 0, which 
causes it to produce white fumes 
in the air. Water at 60° will 
absorb over 450 times its volume 
of the gas, producing the liquid known as "Muriatic 
AcidP It dissolves the metals, and forms chlorides. 
When pure it is colorless, but has ordinarily a yellow 
tinge, due to various impurities. Its tests are H 3 N, with 
which it forms a white cloud of sal-ammoniac fumes, 
and silver nitrate, from which it precipitates AgCl. With 
HN0 3 it makes aqua-regia,* or royal ivater, so called 
because it dissolves Au, the " king of the metals ; " CI is 
set free, which, in its nascent state, attacks the Au and 
combines with it. 

* Boil HC1 in a test tube with fragments of gold-leaf, They will not dissolve. 
Add a few drops of HN0 3 , and a yellow solution of gold chloride will he quickly 
formed. 




Preparing HC1. 



10b INORGANIC CHEMISTRY. 

Calcium Hypochlorite (CaCl 2 2 ) is an ingredient 
of chloride of lime or bleaching powder. This is prepared 
by passing a current of CI oyer pans of fresh slacked 
lime. It is much used in bleaching and as a disin- 
fectant. 

Calcium C?iloride, the other compound of bleach- 
ing powder, was made in preparing C0 2 (see p. 74). It 
is used by chemists for drying gases. It absorbs H 2 so 
greedily that in the open air it will soon dissolve. 

Beomike — named from its bad odor — is a poisonous, 
volatile, deep-red liquid, with the general properties of 
CI.* It is principally found in sea- water, forms bromides 
with the metals, and is used in photography and medicine. 

Fluoeike is the only element that will not unite with 
0. It exists, in small quantities, in the enamel of the 
teeth. It is found in Derbyshire or fluor spar (CaF 2 ), of 
which beautiful ornaments are made. It unites with H, 
forming hydrofluoric acid (HF), noted for its corrosive 
action on glass.f (See Appendix.) This eats out the 
silica or sand from the glass, and is therefore used for 
etching labels on glass bottles and on shop windows. — 
Example : Powdered fluor spar is placed in a lead tray, 
and covered with dilute H 2 S0 4 . The heat of a lamp ap- 
plied beneath, for a moment only, liberates the gas in 
white fumes very rapidly. The plate of glass is covered 
with wax, and the design to be etched is traced upon it 
with a sharp-pointed instrument. This is then laid over 
the tray, and the escaping gas soon etches the lines laid 

* Br is the only element, except Hg, which is liquid at ordinary temperatures, 
t So delicate is the test that by this means the presence of F has been de- 
tected in fossil teeth. 



TME HALOGENS 107 

bare into an appearance like ground glass. A solution of 
HF in H 2 is often sold for this purpose. It is kept in 
lead or gutta-percha bottles, combines with H 2 with a 
hissing sound, like red-hot iron, and must be handled 
with care, as a minute drop even will sometimes produce 
an ulcer. 

Iodike is named from its beautiful violet-colored vapor. 
It is made from kelp (the ashes of sea-weed), and is found 
in sea-water and in some mineral springs. It crystal- 
lizes in bluish-black scales, emits a smell resembling that 
of CI, sublimes* slowly, and is deposited in crystals on 
the sides of the bottle in which it is kept. I is sparingly 
soluble in H 2 0, but readily in ether or alcohol. It in- 
flames spontaneously when in contact with phosphorus, f 
Its compounds with the metals, called the iodides, are re- 
markable for their variety and brilliancy of color. (See 
Appendix.) It stains cloth a yellowish tint, which may 
be removed by a solution of potassium iodide. Its test is 
starch, forming the blue iodide of starch. J I reveals the 
presence of this substance in potatoes, apples, etc. § It is 
much used in medicine to scatter scrofulous or cutaneous 
eruptions and swellings. 



* A body is said to sublime when it rises as vapor and condenses in the solid 
form ; when it condenses as a liquid it is said to distil. 

t Place on a clean, white dish a few scales of iodine and a bit of phosphorus as 
large as a pea. They will soon combine, igniting the phosphorus and subliming 
a part of the iodine. » 

% Mix one or two drops of a solution of potassium iodide with a little dilute 
starch mucilage ; no change of color will occur. Add a single drop of CI water 
to the mixture ; an immediate coloration will occur, owing to the combination 
of the CI with the K, while I is set free, which acts upon the starch. Add a little 
more chlorine water ; the color disappears, owing to the formation of chlorine 
iodide, which is without action on starch. 

§ Pour a few drops of a solution of iodine in alcohol on a freshly-cut potato or 
apple. Blue specks will show the presence of starch. 



108 



INOR GANIC CHEMISTR F. 



BORON, 

Symbol, B Atomic Weight, 10.9. 

!Bo?~on is found in nature in combination -with 0, as 
boracic acid. This is abundant in the volcanic districts 
of Tuscany.* Along the sides of the mountains, series 

Fig. U6. 




Preparing Boracic Acid. 

of basins are excavated and filled with cold water from 
the neighboring springs. Into these basins the jets of 
steam, charged with boracic acid, are conducted. The 
H 2 absorbs the acid, and becomes itself heated to the 
boiling-point. It is then drawn off into the next lower 
basin. This process is continued until the bottom one is 
reached, when the solution runs into leaden pans heated 
by the steam from the earth ; here the H 2 is evaporated, 
and the boracic acid collected. 

* Throughout an area of nearly thirty miles, is a wild, mountainous region, of 
terrible violence and confusion. The surface is ragged and blasted. Everywhere 
there issue from the ground jets of steam, filling the air with most offensive 
odors. The earth itself shakes beneath the feet, aud frequently yields to the 
tread, engulfing man and beast. "The waters below are heard boiling with 
strange noises, and are seen breaking out upon the surface. Of old, it was re- 
garded as the entrance to hell. The peasants pass by in terror, counting their 
beads and imploring the protection of the Virgin." 



SILICON. 109 

%01'ax (Na 2 0, 2B 2 3 , 10H 2 O) is a salt of this acid. 
It is a natural production, obtained by the drying of cer- 
tain lakes in Thibet, and lately found in California. 
When dissolved in alcohol it giyes a peculiar green tint 
to the flame. This is an easy test of the presence of this 
acid. Borax is employed in welding. It dissolves the 
oxide of the metal, and keeps the surface bright for sol- 
dering. It softens hard water by uniting with the soluble 
salts of lime or magnesia, and making insoluble ones 
which settle and form a thin sediment in the bottom of 
pitchers in which it is placed.* 



SILICON. 

Symbol, Si Atomic Weight, 28 Specific Gravity, 2,49, 

Sources. — Silicon is found in combination with as 
silica (silicic anhydride, Si0 2 ), commonly called silex or 
quartz. So abundant is this oxide that it probably com- 
prises nearly one-half of the earth's crust. (See Geology, 
p. 40.) It forms beautiful crystals and some of the most 
precious gems. When pure, it is transparent and colorless, 
as in rock crystal. Jasper, amethyst, agate, chalcedony, 
blood-stone, chrysoprase, sardonyx, etc., are all common 
flint-stone or quartz, colored with some metallic oxide. 
The opal is only Si0 2 and H 2 0. Sand is mainly fine quartz, 
which, when hardened and cemented, we call sandstone. 
Yellow or red sand is colored by iron-rust. 

Properties. — It is tasteless, odorless, and colorless. It 

* Borax is also extensively used in " blow-pipe analysis." When it is melted 
with chromium oxide, it gives an emerald green ; with cobalt oxide, a deep blue; 
with copper oxide, a pale green ; with manganese oxide, a violet. 



110 INORGANIC C HE MIS TRY. 

seems very strange to call such an inert substance 
an anhydride ; yet it readily unites with the alkalies, 
neutralizes their properties, and forms a large class of 
salts known as the silicates, which are found in the most 
common rocks. — Example : feldspar, found in granite. 

Silica in Soil and Tla?its.— Silica is insoluble 
in H 2 0, unless it contains some alkali. When the sili- 
cates, so abundant in rocks, disintegrate and form soil, the 
alkali and silica are both dissolved in the water, and taken 
up by the roots of plants. We see the silex on the surface 
of scouring-rushes and sword-grass, which cut the fingers 
if handled carelessly. It gives stiffness to the stalks of 
wheat and other grains, and produces the hard, shiny 
surface of bamboo, corn, etc. 

"Petrifaction . — Certain springs contain large quan- 
tities of some alkaline carbonate ; their waters, therefore, 
dissolve silica abundantly. If we place a bit of wood in 
them, as fast as it decays, particles of silica will take its 
place — atom by atom — and thus petrify the wood. The 
wood has not been changed to stone, but has been replaced 
iy stone. 

Compounds. — The Silicates. — Glass* is a mixture 

* Glass was known to the ancients. Hieroglyphics, that are as old as the 
sojourn of the Israelites in Egypt, represent glass-blowers at work, much after 
the fashion of the present. In the ruins of Nineveh, articles of glass, such as 
vases, lenses, etc., have been discovered. Mummies, three thousand years old, 
are adorned with glass beads. The inventor is not known. Pliny tells us that 
some merchants, once encamping on the sea-shore, found in the remains of their 
fire bits of glass, formed from the sand and ashes of the sea-weed by the heat ; 
but this is impossible, as an open fire could not be sufficient to melt these 
materials. In the fourth century, the glass-works at Alexandria produced most 
exquisite ornaments, with raised figures beautifully cut and gilded. As late, 
however, as the twelfth century, a house with glass windows was esteemed 
something magnificent ; and we read that, during Queen Elizabeth's reign, when 
the Duke of Northumberland came to town to pass the winter, the windows of 
his castle were taken out and packed away for safe-keeping until spring. 



SILICON. Ill 

of several silicates. There are four varieties used in the 
arts. 1. Windoiv or plate glass is composed of silicates of 
calcium and sodium. It is made by heating white sand, 
sal-soda, and lime in clay crucibles for about forty-eight 
hours, when the materials fuse and combine into a double 
silicate. The Ca hardens and gives lustre; the Na ren- 
ders the glass fusible, but imparts a green tint. 2. Bohe- 
mian glass consists of silicates of calcium and potassium. 
Unlike Na, K gives no color. 3. Flint-glass* or crystal 
contains silicates of potassium and lead. The latter is 
used in large quantities and produces a soft, lustrous 
glass, which can be ground into imitation gems, table- 
ware, chandelier pendants, prisms, etc. 4. Green bottle- 
glass is made of silicates of calcium, sodium, aluminum, 
and iron. The last gives the opaque green of the com- 
mon junk bottle. 

Coloring Glass, — A small quantity of some metallic 
oxide melted with the glass furnishes any tint desired : 
Co gives a beautiful sapphire blue ; Au or Cu, a ruby-red ; 
Mg, a violet ; U, a yellow; As, a soft white enamel, as in 
lamp-shades ; and Sn, a hard enamel, as in watch-faces. 

&?inealing Glass. — If the glass utensils were 
used immediately, they would be found extremely brittle, 
and would drop in pieces in the most unaccountable way. 
The heat of the hand or a draft of cool air would some- 
times crack off the thick bottom of a tumbler. They are 
therefore cooled very gradually for days, which allows 
the particles to assume their natural place, and the mo- 
lecular attractions to become equalized, f 

* So called because pulverized flint was formerly used for sand. 
t This principle is beautifully illustrated by the philosophical toy known as 
the " Prince Rupert's Drop." (See Physics, p. 46.) 



112 INORGANIC CHEMISTRY. 

Orname?ilat Wa7*e. — Venetian balls or paper 
weights are made by arranging bits of colored glass in 
the form of fruits, flowers, etc., and then, inserting them 
in a hollow globe of transparent glass, still hot, the work- 
man draws in his breath, and the pressure of the air 
above collapses the globe upon the colored glass, and 
leaves a concave surface in the opposite side of the weight. 
The lens form always magnifies the size of the figures 
within. 

2ubes a?id !Beads. — In making glass tubing, the 
workman inserts his iron blowing-tube in a pot of melted 
glass, and gathers upon the end a suitable amount; 
drawing this out, he blows into the tube, swelling the 
glass into a globular form. Another dip into the pot and 
another blow increase its size, until at last a second 
workman attaches an iron rod to the other end. The 
two men then separate at a rapid pace. The soft glass 
globe diminishes in size as it lengthens, until at last it 
hangs between them a glass tube of a hundred feet in 
length, and perhaps only a quarter of an inch in diameter. 

For making beads, glass tubes are cut in short pieces, 
and then worked about in a mixture of wet ashes and 
sand, until they are filled. They are next put with loose 
sand in a cylinder rapidly revolving over a hot furnace. 
The heat softens the glass, but the mixture within presses 
out the sides, and the sand grinds the edges, until at last 
the beads become round and perfect, and are taken out 
ready for market. 



SULPHUR. i!3 

SULPHUR. 

Symbol, S Atomic Weight, 32 Specific Gravity, 2, 

Sources. — S is found native in volcanic regions. It is 
mined at Mount zEtna in great quantities. United 
with the metals it forms sulphides, known as cinnabar, 
iron pyrites, galena, blende, etc. Combined with it 
exists in gypsum (plaster), heavy spar, and other sul- 
phates. It is found in the hair, and many dyes contain 
Pb which unites with the S, and forms a black compound 
that stains the hair. It is contained in eggs, and so tar- 
nishes our spoons by forming a sulphide of silver. It is 
always present in the flesh, and hence manifests itself in 
our perspiration. In commerce it is sold as brimstone, 
formed by melting S and running it into moulds ; also 
as flowers of sulphur, obtained by sublimation. 

Properties. — It is insoluble in H 2 0, and hence taste- 
less. Its solvents are carbon disulphide (CS 2 ) ? oil of tur- 
pentine, and benzole. It is a non-conductor of heat, and 
crackles when we grasp it with a warm hand. It mani- 
fests itself under four allotropic forms: 1st, octahedral 
crystals ; 2d, prismatic crystals ; 3d, an amorphous (with- 
out form) or uncrystallized state; and 4th, a viscid 
condition. The last is the most interesting. — Example : 
When S is melted, and then heated more strongly, it 
changes to a thick, viscid, dark-colored liquid resembling 
molasses. If this is poured into cold water, it becomes 
elastic like india-rubber. In this form it is used for tak- 
ing impressions of medals, coins, etc. (See Appendix.) 



lllj. INORGANIC CHEMISTRY. 

Uses. — On account of its ready inflammability , S is 
employed in the making of matches and gunpowder, hut 
its chief consumption is in the production of H 2 S0 4 . 

Compounds. — Sulphurous Anhydride, S0 2 , an 
irrespirable, suffocating gas, is formed by S burning in the 
air, as in the lighting of a match. It is very poisonous, 
and extinguishes combustion. If our " chimney burns * 
at any time, we can easily quench the flame by pouring a 
little S into the stove. 

Uses. — SO 2 is used for bleaching silk, straw, and 
woollen fabrics. CI turns them yellow, but S0 2 unites 
with the coloring matter, and forms a colorless compound. 
Its action is therefore very different from that of CI. — 
Example : A red rose, bleached in the fumes of burning 
S, can be restored to its original color by very dilute 
H 2 S0 4 . This acid being stronger, neutralizes the action 
of the S0 2 . New flannels, washed in strong soap, turn 
yellow, because the alkali of the soap unites with the S0 2 
used in bleaching the cloth, , and thus sets free the origi- 
nal color. S is also frequently employed to check fer- 
mentation, as when it is burned in a barrel before filling 
with new cider. 

Sulphuric Anhydride, S0 3 , may be prepared by 
the oxidation of S0 2 or by removing H 2 from H 2 S0 4 . 
It is often called anhydrous sulphuric acid. If Nord- 
hausen acid * be heated, the vapors may be condensed in 
a mass of silky, crystalline fibres of S0 3 . This will show 
no acid reaction, will not redden blue litmus-paper, and, 
if the fingers are dry, can be molded like wax. If it be 
dropped into H 2 0, it will hiss like a red-hot iron, and 

* So named from the German town near which it was formerly made by the 
distillation of green vitriol (iron sulphate). 



S VL P HUB. 



115 




forming H 2 S0 4? will exhibit all the properties of that 
corrosive substance. 

Sulpfiuric Acid, Oil of Vitriol, is the king of the 
acids. It is of the utmost importance to the manufac- 
turer and chemist, as it is used in the preparation of 
nearly all other acids, and forms many valuable com- 
pounds. 

Preparation. — If we burn a little S in a bot- Fi 9- w- 
tie it will soon become filled with a white 
cloud of SO 2 - Now another atom of would 
make this S0 3 , sulphuric anhydride. Nitric 
acid, it will be remembered, easily parts with 
its 0. So if we stir the S0 2 with a swab wet 
in aqua-fortis, we shall quickly see the familiar 
hyponitric acid fumes, indicating that the acid 
has been decomposed and has given up its 0. 
Add a little water and shake the jar thoroughly. On 
testing the liquid with a few drops of a solution of 
barium chloride, - the beautiful white precipitate will 
prove the presence of H 2 S0 4 .* 

The Ma?itifacture of Sulphur ic Acid on a 
large scale is based on the principle of the preceding 
illustration. The process is facilitated by the curious 
fact that the nitric oxide (NO) produced by the decom- 
position of the HN0 3 h as *he property of acting as a car- 
rier of between the common air and S0 2 , whereby it 
can oxidize an almost indefinite quantity, thus forming 
S0 3 , which, in the presence of H 2 0, will be at once con- 
verted into H 2 S0 4 . S is burned in a current of air in fur- 
naces A, A. In the stream of heated gas is suspended an 



Making 
H a S0 4 . 



* The reaction in making the acid maybe thus expressed: 2KNX) 3 +SO a = 
H a S0 4 +2NO a . 



116 



IN OR GANIC CHE3IISTR F. 



iron pot, b, charged with a mixture of sodium nitrate and 
H 2 S0 4 . Y T apors of HN0 3 are thus set free, and these 
pass on mixed with S0 2 and excess of atmospheric air. 




Manufacture of H 2 S0 4 . 



The mingled gases pass into immense chambers, F, of 
sheet lead. A shallow layer of H 2 0, d, covers the floor, 
and the intermixture and chemical action of the gases 
are further favored by the injection of jets of steam, e, 
supplied from the boiler, G. 

The chemical action which ensues may be explained 
as follows :— The nitric acid is quickly reduced to nitric 
oxide, NO. This takes up an atom of from the air, 
becoming N0 2 , and flies back to the S0 2 making a mole- 
cule of S0 3 , which, with a molecule of H 2 becomes 
H 2 S04, a molecule of sulphuric acid. The NO once 
more seeks the air and returns laden with for the S0 2 . 
This process continues until the chamber becomes so full 



SULPHUR. 117 

of the sluggish N that the other gases are nearly lost in 
it, when they are allowed to escape gradually. The weak 
sulphuric acid which collects on the floor is drawn off 
and condensed by evaporation in lead pans, and finally, 
when it begins to corrode the lead, in platinum or glass 
stills. It is lastly put in large bottles packed in boxes 
called carboys, when it is ready for transportation. 

Properties. — It is a dense, oily liquid, without odor, 
and of a brownish color. Its affinity for moisture is most 
remarkable. If exposed in an open bottle it gradually 
absorbs water from the air,- and increases in bulk, 
sometimes even doubling its weight. It blackens wood 
and other organic substances, by taking away their H 2 
and leaving the C-* When mixed with H 2 0, it occupies 
less space than before, and produces much heat; 4 parts 
of acid to 1 of H 2 will boil a test-tube of water. It 
commonly contains lead, which falls as a milky precipi- 
tate (PbS0 4 ) when the acid is diluted. It is the strongest 
of the acids, and will displace the others from their com- 
pounds. It stains cloth red, but the color can be re- 
stored by an alkali, if applied immediately. Its test is 
barium chloride, which forms a white, cloudy precipi- 
tate. In this way a drop of H 2 S0 4 can be detected in a 
quart of H 2 0. 

ITydrogen Sulpiride, H 2 §, Sulphuretted Hydrogen, 
Sulphydric Acid. — This gas is produced in the decay of 
organic matter, and is always found near cess-pools, drains, 
and sinks, turning lead paint black and emitting a dis- 
agreeable smell. It gives the characteristic odor to the 



* Strong oil of vitriol poured on a little loaf-sugar moistened with hot water, 
will cause an energetic boiling and a copious formation of black charcoal. Sugar 
consists of water and charcoal, and gives up the former to satisfy the acid. 



118 



IN OR GANIC CHE3IISTR T. 




M 9* &• mineral waters of Avon, 

Clifton, Sharon, and 
other celebrated sulphur 
springs. It is prepared 
by the action of dilute 
H 2 S0 4 upon ferrous sul- 
phide (FeS). The reac- 
tion is as follows: FeS + 
H 2 S0 4 = FeS0 4 +H 2 S. 

H 2 S has the disgusting 
odor of rotten eggs. It is 
Preparing h £ s. very poisonous, and there- 

fore makes an open sewer 
destructive to health. Its solution in H 2 is much used 
in the laboratory to precipitate many of the metals as 
sulphides. Its test is lead acetate (sugar of lead.) 

Carbo?i H>istdj)hide, CS 2 , is produced by passing 
the vapor of S over red-hot coals. It is a volatile, color- 
less liquid, and has never been frozen. The fact that 
a yellow, odorless solid thus unites with a black, odorless 
solid to form such a colorless, odoriferous liquid, illus- 
trates very finely the power of chemical affinity. CS 2 
readily dissolves S, P, and I. It is a powerful refractor 
of light, and is used for filling hollow, glass prisms 
employed in experiments with the solar spectrum. In 
its combustion it unites with 0, forming C0 2 and S0 2 . 



PRACTICAL QUESTIONS. 

1. If chlorine water stands in the sunlight for a time, it will only 
redden a litmus-solution. Why does it not bleach it ? 

2. Why do tinsmiths moisten with HC1, or sal-ammoniac, the 
surface of metals to be soldered ? 



PHOSPHORUS. 119 

3. How much H CI can be made from 25 lbs. of common salt ? 

4. What weight of NaCl would be required to form 25 lbs. of 
muriatic acid ? 

5. H CI of a specific gravity of 1.2 contains about 40 per cent, of 
the gas. This is very strong commercial acid. What weight could 
be formed by the HC1 acid gas produced in the reaction named in 
the preceding problem ? 

6. What is the difference between sublimation and distillation ? 

7. Why do eggs discolor silver spoons ? 

8. Explain the principle of hair-dyes. 

9. Why is new flannel apt to turn yellow when washed ? 

10. Is it safe to mix oil of vitriol and water in a glass bottle ? 

11. What is the color of a sulphuric acid stain on cloth ? How 
would you remove it ? 

12. What causes the milky look when oil of vitriol and water are 
mixed ? 

13. What is the chemical relation between animals and plants ? 
Which perform the office of reduction, and which of oxidation ? 

14. How many pounds of S are contained in a cwt. of H 2 S0 4 ? 

15. How much and H 2 are needed to change a ton of S0 2 to 
H 2 S0 4 ? 

16. How much in a lb. of H 2 S0 4 ? 

17. State the analogy between the compounds of and S. 



PHOSPHORUS. 

Symbol, P Atomic Weight, 31 Specific Gravity, 1,83, 

The name Phosphorus signifies light-bearer, given be- 
cause this substance glows in the dark. It was called by 
the old alchemists " the son of Satan." * 



* The following singular event is said to have occurred many years before the 
reputed discovery of phosphorus by Brandt in 1669. A certain Prince San Severo, 
at Naples, exposed some human skulls to the action of several reagents, and 
then to the heat of a furnace. From the product he obtained a substance which 
burned for months without apparent loss of weight. San Severo refused to 



mo 



IN OR GANIC CHEMISTR Y. 



Fig. 50. 



Sources. — It exists in small quantities in rocks, and by 
their decay passes into the soil, is taken up by plants, is 
then stored in their seeds (wheat, corn, oats, etc.), and 
finally passes into our bodies. As calcium phosphate 

("phosphate of lime"), it is a 
prominent constituent of our 
bones.* Phosphorus is so neces- 
sary to the operation of the brain 
that the alchemists had a saying, 
" No phosphorus, no brains." 

Preparation. — It is prepared 
in immense quantities from 
bones. These are first calcined 
to whiteness to burn out the 
animal matter, then treated with 
H 2 S0 4 to remove the Ca (pp. 140, 230), and lastly heated 
to a high temperature with C to deoxidize the phospho- 
rus, which distils as a vapor, and is condensed under H 2 0. 
Properties. — It is a waxy, translucent solid, at all tem- 
peratures above 32° emits a feeble light, melts at 111°, 
and ignites at a little higher temperature. It should 
be handled with the utmost care, always kept and cut 
under H 2 0, and never used except in very small quanti- 
ties. Its burns are deep and dangerous. It is poisonous, 
and its vapor produces horrible ulcerations of the jaw- 
bone in workmen who use it. 

Amorphous J^orm. — Heated for several hours at 




Manufacture of Phosphorus . 



divulge the process, as he wished his family vault to be the only one to possess 
a ''perpetual lamp" the secret of which he considered himself to have dis- 
covered. 

* " Of phosphorus every adult person carries enough (If lbs.) about with him 
in his body to make at least 4,000 of the ordinary two-cent packages of friction 
matches, but he does not have quite sulphur enough to complete that quantity of 
the little incendiary combustibles,"— Nichols's Fireside Science. 



PHOSPHORUS. 121 

a temperature of about 500°, in a close vessel filled 
with N or C0 2 , the melted phosphorus changes into a 
brick-red solid, and seems to lose all its former proper- 
ties. It is now insoluble in CS 2 , which can be used to 
dissolve out every trace of the common form. Its spe- 
cific gravity is increased to 2.14. It can be handled with 
impunity, carried in the pocket like so much snuff, and 
even heated to nearly 400° without taking fire. At a 
little over 500°, however, it changes into the common 
form and bursts into a blaze. 

Uses. — Jlfatc/ies. — The principal use of phosphorus is 
in the manufacture of matches. 1. The Lucifer Match. — 
The bits of wood are first dipped in melted S and dried ; 
then in a paste of phosphorus, nitre, and glue, which 
completes the process. The object of the nitre is to fur- 
nish O to quicken the combustion. Instead of this, potas- 
sium chlorate is sometimes used ; it can be recognized by 
a crackling sound and jets of flame when ignited. The 
tips are colored by red-lead, or Prussian blue, mixed in 
the paste. When a match is burned, the reaction is as 
follows : first, the friction ignites the phosphorus, which 
burns, forming P 2 5 ; * this produces heat enough to in- 
flame the S, which makes S0 2 ; lastly, the wood takes 
fire, and forms C0 2 and H 2 0. Thus there are four com- 
pounds produced in the burning of a single match. 

2. The Safety Match. — The pieces of wood are dipped 
into melted paraffine (see p. 205) and dried. They are 



* The burning phosphorus produces a very luminous flame, because of the 
reflection of light from the dense vapor (P 8 O s ). The following experiment is 
very suggestive in this connection : Ignite a bit of phosphorus placed upon a 
sheet of white paper. The paper will be blackened just where the phosphorus 
lay, but will not take fire; and after the flame is extinguished, one can write 
upon it with pen and ink, close to the edge of the charred portion. 

6 



122 INORGANIC CHEMISTRY. 

then capped with a paste of potassium chlorate, sulphide 
of antimony, powdered glass, and gum-water. They 
ignite only when rubbed on a surface covered with a 
mixture of red phosphorus and powdered glass. 

jP?iosphoresce?ice* — The luminous appearance of 
putrefying fish and decayed wood is well known. The 
latter is sometimes called " fox-fire." The " glow-worm's 
fitful light " is associated with our memory of beautiful 
summer evenings. In the West Indies, fire-flies are found 
that emit a green light when resting, and a red one when 
flying. They are so brilliant that one will furnish light 
enough for reading. The natives wear them for orna- 
ments on their bonnets, and illuminate their houses by 
suspending them as lamps. — The ocean occasionally takes 
on strange colors, and the sailor finds his vessel plowing 
at one time apparently a furrow of fire, and at another 
one of liquid gold. The water is all aglow, and the flames 
seem to leap and dance with the waves or the motion of 
the ship. The phenomenon is produced by multitudes 
of animalcules which frequent certain seas. Phosphores- 
cence is generally attributed to the gradual oxidation of 
the phosphorus secreted by the animal or plant. 

Compounds.— IPydroge?i / P?iosp?iide> H 3 P, Phos- 
phuretted Hydrogen, is formed in the decomposition of 
bones and organic substances. It is a poisonous gas, 
remarkable for its disgusting odor, for igniting spontane- 
ously on coming to the air, and for the singular beauty of 
the rings formed by its smoke. It is prepared by heat- 
ing in a retort a strong solution of potash containing a 
few bits of phosphorus. It has been thought by some 
that the Will-o'-the-wisp, Jack-o'-the-lantern, etc., as seen 
near graveyards and in swampy places, are produced by 




128 



Preparation of H 3 P. 

this gas coming off from decaying substances, and igniting 
as it reaches the air. 



ARSENIC 



Symbol; As. . . .Atomic Weight, 75. . . .Specific Gravity, 5,9, 

Volatilizes without fusion at about 356" F. 

As is a brittle, steel-gray metal,* commonly sold, when 
impure, as cobalt. \ If heated in the open air it gives off 
the odor of garlic, which is a test of As. 

* Arsenic very much resembles phosphorus in its general properties, and is 
therefore classified with it, but it conducts electricity moderately, and has a high 
brilliancy. It seems to be intermediate between the non-metals and the metals. 

t Cobalt is a reddish-white metal, found in combination with arsenic. Co 
received its name from the miners, because its ore looked so bright that they 
thought they would obtain something valuable ; but when, by roasting, it crum- 
bled to ashes, they believed themselves mocked by the evil spirit (Kobolt) of the 
mines. The oxide of cobalt makes a beautiful blue glass, which, when ground 
fine, is called smalt. It is used for tinting paper, and by laundry women to give 
the finished look to cambrics, linen, etc. Its impure oxide, called zaffer, imparts 
the blue color to common earthenware and porcelain. The chloride (CoCl a jis used 
as a sympathetic ink. Letters written with a dilute solution of it are invisible 
when moist with the H 2 absorbed from the air, but on being dried at the 
stove, again become blue. If the paper be laid aside the writing will disap- 
pear, but may be revived in the same manner. A winter landscape may be 
drawn with India-ink, the leaves being added with this ink. On being brought 
to the fire it will bloom into the foliage of summer. 



12J+ INORGANIC CHEMISTRY. 

A?*senious Anhydride, As 2 3 .— This is the well- 
known "ratsbane" and is sometimes sold as simply 
" arsenic." 

Preparation. — It is made in Silesia, by roasting arseni- 
cal iron-ore at the bottom of a tower, above which is a 
series of rooms through which the vapors ascend, and 
pass out at a chimney in the top. The As burns, form- 
ing As 2 3 , which collects as a white powder on the walls 
and floors of the chambers above.* 

Properties. — "Arsenic" is soluble in hot H 2 0, and has a 
slightly sweetish taste. It is a powerful poison, doses of 
two or three grains being fatal, although an over-dose 
acts as an emetic. It is an antiseptic, and so in cases of 
poisoning frequently attracts attention by the preserva- 
tion of parts of the body, even twenty or thirty years 
after the murder has been committed. The antidote is 
milk or whites of eggs.f 

Marsh's Test. — There is no other poison which is 
so easily detected. Prepare a flask for the evolution of H. 
Ignite the jet of gas, and hold in the flame a cold porce- 
lain dish. If it remains untarnished, the materials con- 
tain no As. Now pour in through the funnel-tube a 
few drops of a solution of As ; % the color of the flame 
will be seen to change almost instantly, and a copious 
'•metallic mirror" of As will be deposited on the dish. 



* Its removal is a work of great danger. The workmen are entirely enveloped 
in a leathern dress and a mask with glass eyes ; they breathe through a moistened 
sponge, thus filtering the air of the fine particles of arsenic floating through it. 
Yet, in spite of all these precautions, they rarely live beyond forty. 

t The exact chemical antidote is hydrated ferric oxide. In this, as in most 
other cases of poisoning, where the antidote is not at hand, an emetic should be 
taken at once— a tea-spoonful of mustard in a glass of warm water, or even a 
quantity of soap-suds. (See Phijsiology, page 209.) 

i This is made by dissolving a little As 2 O a in HCL 



AR S E NI C. 



125 



indeed, and the utmost care 



Fig. 52. 



The gas formed in this experiment — arseniuretted hydro- 
gen — is very poisonous 
should be used to pre- 
vent its inhalation.* 

Arsenic -J?ati?ig . 
— It is said that the 
peasants in a portion of 
Hungary are accus- 
tomed to eat As, both 
fasting and as a season- 
ing to their food. A 
very minute portion 
will warm, stimulate, 
and aid in climbing 
lofty mountains. The 
arsenic-eaters are de- 
scribed as plump and rosy, and it is said that the young 
people resort to this dangerous substance, as a species of 
cosmetic. They begin with small doses, which are grad- 
ually increased; but if the person ceases the practice, 
all the symptoms of arsenic poisoning immediately 
appear. Horse-jockeys sometimes feed arsenic to their 
horses to improve their flesh and speed. 




Marsh's Test. 



* In a case of poisoning, of course, the contents of the stomach would be 
substituted for the solution of As, and other tests besides this would be em- 
ployed. We can imagine with what care a chemist would conduct the examin- 
ation, and with what intense anxiety he would watch the porcelain dish as the 
flame played upon it, hesitating, and dreading the issue, as he felt the life of a 
fellow-being trembling on the result of his experiment. 



126 IN ORGANIC CHEMISTRY. 



THE METALS. 



THE METALS OF T H E • ALKALIES. 
K, Na, L, C Sj Rb, and H 4 N(?). 



POTASSIUM. 

Symbol, K. . . .Atomic Weight, 39 . . . .Specific Gravity, 0.86. 

Source. — K is found abundantly in the various rocks, 
which by their decomposition furnish it to the plants 
"from which we obtain our entire supply.* 

Preparation. — This metal was discovered by Sir Hum- 
phrey Davy, in 1807. On passing the current of a power- 
ful galvanic battery through potash, the globules of the 
K appeared at the negative pole. The metals Na, Ba, Sr, 
and Ca, were afterward separated in the same manner. 
This discovery constituted a most important epoch in 
chemistry. K is now prepared by distilling in iron bot- 
tles, at an intense heat, potassium carbonate and charcoal. 
The green vapors of K are condensed in receivers of 
naphtha, and CO passes off as a gas. K 2 C0 3 -f-2C=:K2-f 
3 CO. It is a difficult and dangerous process. The vapor 

* " An acre of wheat producing twenty-five bushels of grain and 3,000 lbs. of 
straw, removes about 40 lbs. of potash in the crop. An acre of corn, produc- 
ing 100 bushels, removes in kernel and stalk 150 lbs. of potash and 80 lbs. of 
phosphoric acid. An acre of potatoes, yielding 300 bushels, will remove in tubers 
and tops 400 lbs. of potash and 150 lbs. of phosphoric acid. A pound of wheat 
holds a quarter of an ounce of mineral substances, and a pound of potatoes one- 
eighth of an ounce."— Nichols. 




POTASSIUM. 127 

takes fire instantly on contact with air or water. It also 
absorbs CO, and the compound, if kept, becomes power- 
fully explosive. To prevent this danger, the K is imme- 
diately redistilled. 

Properties. — K is a silvery-white metal, soft enough to 
be spread with a knife, and light enough to float like cork 
Its affinity for is so great that it is always kept undei 
the surface of naphtha, which contains no 0. K, when 
thrown on H 2 0, decomposes it, sets 
free one atom of H,and forms KHO. %g% *\__ 

The heat developed is so great, that 
the H catches fire and burns with 



some volatilized K, which tinges the 

' & Kon H 2 0. 

flame with a beautiful purple tint. 

If the H 2 be first colored with red litmus, it will become 

blue by the alkali formed. 

Compounds. — Potash, K 2 0, has so great an affinity for 
H 2 that the anhydrous form is rarely prepared. Its 
hydrate, KHO,f is a white solid made from potassium 
carbonate by the action of slacked lime. It is the most 
powerful alkali. It neutralizes the acids, and turns red 
litmus to blue. It is used to cauterize the flesh, and is 
hence commonly called " caustic potash." It dissolves 
the cuticle of the finger which touches it, and so has an 
unctuous feel. It unites with grease, forming soap, in 
the manufacture of which it is extensively used. 

iPolassizim Ca?*bo?iate, K 2 C0 3 , % Pearlash, " Car- 
bonate of Potash" is obtained in the following manner : 

* Cut the metal in small pieces and cover it with a receiver, since the melted 
globule bursts at the close of the experiment. 

t K 2 + H 2 0=2(KH0), or 2 molecules of potassium hydrate. 

X The symbol K 2 C0 3 is merely a list of the elements, and the proportion of 
each contained in a molecule of potassium carbonate. It is called an empirical 



128 INORGANIC CHEMISTRY. 

Potash exists in plants, combined with various acids, such 
as tartaric, malic, oxalic, etc. When the wood is burned, 
the organic acids are decomposed by the heat, and the 
C0 2 combines with the K 2 0, forming K 2 C0 3 . The ashes 
are then leached and the lye is evaporated, when the salt 
crystallizes. This forms potassium carbonate, the "pot- 
ash" of commerce. When refined it is called "pearlash." 
Where wood is abundant, immense quantities are burned 
solely for this product. Birch gives the purest potash, 
while the leaves of a tree furnish twenty-five times as 
much as the heart.* 

Hydrogen "Potassium Carbonate, \ H KC0 3 , Sal- 
eratus. "Bicarbonate of Potash "l is prepared by pass- 



formula. It can be written thus : K 2 0.C0 2 , and is then termed a rational 
formula, since it indicates the compounds which, put together, form the car- 
bonate. One objection to the latter formula is that we do not know that the 
separate compounds still exist in the salt. The empirical formula contains all 
that is positively decided. 

* Vast deposits of potash have been opened up to us at the Stassfurth salt 
mines in Germany, the supply from which is more than from the wood-ash 
sources of the whole world. " Only about 13,000 tons of potash were sent to mar- 
ket from the United States and British America in 1870, and yet from Stassfurth, 
where a dozen years ago it was not supposed that a single ton could be produced, 
30,000 tons of potassium chloride were manufactured and supplied to consumers 
upon both continents during the following year. The surface salts at these mines, 
which hold the potash, are practically inexhaustible, and millions of tons will 
be supplied in succeeding years."— Fireside Science. 

t The molecule of carbonic acid is H 2 C0 3 . In potassium carbonate, K 2 C0 3 , 
both the atoms of H contained in the carbonic acid are replaced by the metal K ; 
in hydrogen potassium carbonate, HKC0 3 , only one atom of H is thus replaced. 
In this way two classes of salts are derived ; the so-called acid salts, where only 
one atom of H has been replaced, and the neutral salts, where both atoms have 
been replaced by a metal. Thus hydrogen potassium sulphite, HKS0 3 , is an acid 
salt, and potassium sulphite, K 2 S0 3 , is a neutral salt. An acid containing two 
atoms of H, capable of displacement by a metal, is said to be dibasic, as H 2 S0 4 , 
H 2 C0 3 ; and one having three atoms capable of displacement is termed tribasic. 
Example : H 3 P0 4 , which forms three different salts from Na, the H being dis- 
placed from the acid step by step. 

$ If we double the number of atoms of each element in a molecule of hydro- 
gen potassium carbonate, the rational formula will be K 2 0.H 2 0.2C0 3 ; hence 
this salt is commonly called the bicarbonate of potash. 



POTASSIUM. 129 

ing C0 2 through a strong solution of potassium car- 
bonate. 

"Potassium Nitrate, KN0 3 ,* Nitrate of Potash, 
Saltpetre, Nitre, — This salt is found as an efflores- 
cence on the soil in tropical regions, especially in India- 
It is obtained thence by leaching.f It is formed artifi- 
cially by piling up great heaps of mortar, refuse of sinks, 
stables, etc. " In about three years, these are washed, and 
each cubic foot of the mixture will furnish four or fiye 
ounces of saltpetre." It dissolves in about three and a 
half times its weight of cold H 2 0. 

Properties and Uses. — It is cooling and antiseptic; 
hence it is used with common salt (NaCI) for preserving 
meat. It parts readily with its 0, of which it con- 
tains nearly 48 per cent., and deflagrates brilliantly. 
Every government keeps a large supply on hand for 
making gunpowder, in the event of war. Gunpowder is 
composed of about three parts charcoal, and one each of 
saltpetre and sulphur — the proportion varying with the 
purpose for and the country in which it is made. Its ex- 
plosive force is due to the expansive power of the gases 
formed. At the touch of a spark the saltpetre gives up 
its to burn the S and C. The reaction that ensues 
maybe approximately represented as follows: 2KN0 3 + 
S+3C=K 2 S+N 2 + 3C0 2 . 

N and C0 2 are gases, and in the great heat of perhaps 
2,000°, high enough to melt silver or copper, the K 2 S be- 
comes a vapor. With the sudden increase of temperature 
they all expand till they occupy at least 1,500 times the 

* In this salt the H of HN0 3 is replaced by K. (See page 23, note.) 

t It was manufactured in the Mammoth Cave, Kentucky, during the war of 

1812. The remains of the works, and even the deep ruts of the wagon-wheels, 

are still to he seen, preserved in the pure, still air. 



ISO INORGANIC CHEMISTRY. 

space of the powder. — Millek. The bad odor of burnt 
powder is due to the slow formation of H 2 S in the resid- 
uum. Fireworks are composed of gunpowder ground 
with additional C and S, and some coloring matter. Zinc 
filings produce green stars, steel filings variegated ones. 
Sr.2N0 3 tinges flame with crimson. Salts of copper give 
a blue or green light, and camphor a pure white one. 

Potassium Chlorate, KC10 3 , is a white, crystallized 
salt much used in preparing oxygen, making matches, 
fireworks, etc. It is a powerful oxydizing agent.* 

Potassium SicJiromate \ is a red salt highly 
valued in dyeing, calico-printing, and photo-lithography. 
If we mix a solution of this salt and one of sugar of lead, 
a yellow-colored precipitate will be formed, known in the 
arts as chrome-yellow (lead chromate). 



SODIUM. 

Symbol, Ma. . . .Atomic Weight, 23. . . .Specific Gravity, 0,972, 

This metal is found principally in common salt. Its 
preparation is similar to that of K, but is more easily 
managed. It is very like K in appearance, properties, 

* Examples : 1. Cover a bit of phosphorus, no larger than a mustard seed, 
with finely powdered KC10 3 (See Appendix), wrap in a paper and lay it on an 
anvil. Upon striking the mixture with a hammer, a sharp detonation will 
ensue. 2. Place in a wine-glass five or six pieces of phosphorus as large as a 
grain of wheat, and cover with crystals of KC10 3 . Fill the glass two-thirds full 
of H 2 0. By means of a pipette, or a glass funnel, introduce into immediate con- 
tact with the KC10 3 a few drops of strong H,S0 4 . A violent chemical action 
will immediately ensue, and the phosphorus will bum under the water with vivid 
flashes of light. 

t Chromic anhydride (Cr 2 3 ) is an oxide of chromium {chroma, color), a metal 
prized only for its numerous brilliantly colored compounds. It is rather rare, 
and mainly found in chrome iron-stone (FeO.Cr 3 3 ). 



SODIUM. 131 

and reaction. When thrown on H 2 it rolls over its sur- 
face like a tiny silver ball ; if the H 2 be heated, it bursts 
into a bright yellow blaze. The test of all the soda salts 
is the yellow tint which their solution in alcohol gives to 
flame. 

Compounds. — Sodittm Chloride, NaCl, Common 
Salt, is a mineral substance absolutely necessary to the 
life of human beings and the higher orders of animals. 
It does not enter into the composition of tissue, but is 
essential to the proper digestion of the food, and to the 
removal of worn-out matter. (See Physiology, p. 137.) 
Among the many cruel punishments inflicted in China, 
deprivation of salt is said to be one, causing at first a 
most indescribable longing and anxiety, and finally a 
painful death. As salt is so universally necessary, it is 
found everywhere. Our Father, in fitting up a home for 
us, did not forget to provide for all our wants. The quan- 
tity of salt in the ocean is said to be equal to five times 
the mass of the Alps. Salt lakes are scattered here and 
there ; saline springs abound ; and besides these, in the 
earth are stored great mines, probably produced by the 
evaporation of salt lakes in some ancient period of the 
earth's history. Near Cracow, Poland, is a bed five hun- 
dred miles long, twenty miles wide, and a quarter of a 
mile thick. In Spain, and lately in Idaho, it has been 
quarried out in perfect cubes, transparent as glass, so that 
a person can read through a large block. 

Preparation. — On the sea-shore it is manufactured by 
the evaporation of sea-water, each gallon containing 
about four ounces.* At Syracuse, New York, near by 

* Salt is soluble in less than three times its weight of H 2 0. It dissolves 
equally well in hot or cold H 2 0, and a saturated solution (one containing all it 



132 



IXOR GANIC CHE MI STR Y. 



and underneath the Onondaga Lake, is apparently a 
great basin of salt-water, separated from the. fresh -water 
above by an impervious bed of clay. Upon boring 
through this, the saline water is pumped up in immense 
quantities. The H 2 is evaporated by heating in large 
iron kettles over a fire, or in shallow, wooden rats by 
exposure to the sun — whence the name " solar salt." 
If boiled down rapidly, fine table-salt is made ; if more 
slowly, coarse salt, as large crystals have time to form. 
Frequently they assume a "hopper shape," one cube 

Fig. 5k. 





Hopper farm of salt crystals. 

appearing, then others collecting at its edges, and gradu- 
ally settling, until a hollow pyramid of salt-cubes, with 
its apex downward, is formed. 

Uses. — NaCl is used largely as a fertilizer, for preserv- 
ing meats and fish, and for preparing CI, HC1, and the 
various compounds of Na. 



will dissolve) has about 36 per cent. Sea-watei contains about 3 per cent. 
Sodium carbonate was formerly obtained from the ashes of sea-plants, as potas- 
sium carbonate is now from the ashes of land-plants.— Roscoe. 



SODIUM. 138 

Sodium SulpJiate (Na 2 S0 4 , 10H 2 O), Glauber's Salt, 
named from its discoverer, is made in great quantities 
from NaCl, as the first stage in the manufacture of sodium 
carbonate. It is remarkably efflorescent, the salt, by 
exposure to the air, losing its ten molecules of H 2 0.* It 
has a bitter, saline taste and is used in medicine. 

Sodium Carbo?iate (Na 2 C0 3 , 10H 2 O), Sal-soda, is 
used extensively in the arts. It is, therefore, of great 
importance to all consumers of soap, glass, etc., that it 
should be manufactured as cheaply as possible. Le- 
blanc's process of making it from NaCl is now gen- 
erally adopted. The operation comprises two stages: 
Changing, 1. NaCl into Na 2 S0 4 ; and, 2. Na 2 S0 4 into 
Na 2 C0 3 . 

1. A mixture of NaCl and H 2 S0 4 is heated. Na 2 S0 4 
is formed with a copious evolution of HC1. The fumes 
of this gas are conducted into the bottom of a vertical 
flue filled with pieces of coke wet with constantly falling 
H 2 0. The gas is here absorbed and a weak muriatic acid 
formed in great quantities, f 

2. The Na 2 S0 4 is heated with chalk (CaC0 3 ) and char- 
coal. The C deoxidizes the Na 2 S0 4 , changing it into Na 2 S. 
The metals of the Na 2 S and the CaC0 3 change places, 



* Experiment : Make a saturated solution of sodium sulphate, and with it fill 
a bottle. Either put in the glass stopple or cover the top with a thin layer of oil, 
and let the bottle stand. The salt will remain for months without crystallizing ; 
but if it be taken up, and shaken ever so little, the whole mass will instantly 
form into crystals, so filling the bottle that not a drop of water will escape, even 
if it be inverted. Should there be any hesitation in crystallizing at the moment, 
drop into the bottle a minute crystal of the salt, and the effect will instantly be 
seen in the darting of new crystals in every direction. 

t This acid was formerly allowed to escape, causing the destruction of all 
vegetation in the neighborhood. It is now, however, absorbed so perfectly that 
the gases which escape from the top of the chimney will not render turbid a 
solution of silver nitrate (see page 166), showing that there is not a trace of the 
acid left. 



lSIf INORGANIC CHEMISTRY. 

forming Na 2 C0 3 and CaS. Out of this mass, called from 
its color " black-ash/' the Na 2 C0 3 is dissolved,* and then 
crystallized, making the " soda^ ash " of commerce. 

Hydrogen Sodium Carbonate (HNaC0 3 ),t " Bi- 
carbonate of Soda" is the "soda" of the cook-room. 
It is prepared by the action of C0 2 on sodium carbonate. 
The CO 2 may be easily liberated by the action of an acid. 
(See p. 234.) 



AMMONIUM. 

Symbol, H 4 N Molecular Weight, 18, 

This is a compound which has never been separated, but 
it is generally thought to be the base of the salts formed 
by the action of the acids upon the alkali ammonia, which 
in form, color, and lustre closely resemble the corres- 
ponding salts of K. The analogy between its action and 
that of the simple metals is so very striking J that it is 
considered a compound metal, acting the "part of a simple 
one, as Cy does that of a compound halogen (see p. 84). § 



* The insoluble residuum of CaS, and the superfluous coal, form around the 
alkali works a mountain of waste. Attempts have been made to extract the S, 
and at the Paris exposition large blocks thus obtained were exhibited ; but the 
operation has failed of commercial success. 

t The rational formula (see note, page 127) is Na 2 O.H a 0.2C0 3 , whence the 
name bicarbonate of soda. 

% When H 3 N is dissolved in H 2 0, forming H 3 N.H 2 0, the compound may be 
represented as (H 4 N) HO. Comparing this with the formula for caustic potash, 
KHO, we see that the group of elements H 4 N corresponds to the K. Thus we 
may call a solution of H 3 N, ammonium hydrate, af? one of potash is a potassium 
hydrate. Both act as powerful bases, neutralize the acids and form soaps. 

§ The following experiment is thought by some to be an additional proof of 
the metallic nature of this compound substance. Heat moderately in a test-tube 
half a fluid-iram of Hg with a piece of Na the size of a pea. The two metals 



AMMONIUM. 185 

Compounds — Ammonium CJiloride, H 4 NC1,* Sal- 
ammoniac, is prepared from the ammoniacal liquor of 
the gas-works. (See p. 83.) Its tough fibrous crystals 
reveal no trace of the pungent ammonia, yet it can easily 
be set free, as we have already seen (p. 48). Sal-ammo- 
niac is soluble in H 2 0. It is used in medicine, in the 
preparation of H 3 N and its salts, in dyeing, and also in 
soldering, as it dissolves the coating of the oxide of the 
metal and preserves the surfaces clear for the action of 
the solder. 

Ammonium Carbo?iate, Sal-volatile, Smelling Salts, 
is prepared by the action of chalk upon sal-ammoniac. f 
It is largely used by bakers in raising cake. (See p. 235.) 

Ammonium Nifraie (H 3 N,HN0 3 =:H 4 N,N0 3 ) may 
be readily formed by cautiously adding dilute HN0 3 
to aqua ammonia until the liquid becomes neutral, and 
then evaporating. Long, needle-shaped crystals will 
form. Thus two fiery liquids combine to produce a solid 
having no resemblance to either of them. By heat this 
salt may be converted into H 2 and N 2 0. (See p. 46.) 

will combine, formirig a pasty amalgam. When cold, pour over it a solution of 
sal-ammoniac. The amalgam will immediately swell up to eight or ten times 
its original bulk, retaining, however, its metallic lustre. The ammonium cannot 
be separated from the amalgam, since, on heating, it decomposes, and on being 
thrown into water, H is set free and H 3 N formed. 

* Its rational formula is H 3 N.HC1, whence it is often called hydrochlorate of 
ammonia. 

t It is a sesquicarbonate, but by the constant loss of H 3 N through evapora- 
tion, it becomes crusted with a spongy coat of the "bicarbonate," hydrogen 
ammonium carbonate (H 4 N), HC0 3 , 



136 



INORGANIC CHEMISTRY. 



METALS OF THE ALKALINE EARTHS. 

Ca, Ba, and Sr, 



Compounds. — Calcium 



Fig. 55. 



CALCIUM. 
Symbol, Ca Atomic Weight, 40 Specific Gravity, 157, 

Ca exists abundantly in limestone, gypsum, and in the 
bones of the body.* It commonly occurs as an oxide or 
a carbonate. 

Oxide (CaO), Caustic or 
Quicklime, is obtained by 
heating limestone (CaC0 3 ) 
in large kilns. The C0 2 is 
driven off by the heat, and 
the CaO is left as a white 
solid. 

Fig. 55 shows a form of 
lime-kiln in which the pro- 
cess is continuous. At a, 
I, c, d, are the doors for the 
fuel, ash-pit, etc. The lime- 
kiln is fed at the top from 
time to time, while the lime 
is taken out at / as fast as 
formed. 

Properties. — CaO is a strong alkali, and corrodes the 
flesh. Its test is C0 2 ? producing a milky precipitate of 




Lime-kiln. 



* " There are 5 lbs. of phosphate of lime, one of carbonate of lime, and 3 oz. 
of fluoride of calcium in the body of an adult weighing 154 lbs."— Nichols. 



CALCIUM. 137 

CaC0 3 . It has such an affinity for H 2 0, that fifty-six 
pounds of lime will absorb eighteen pounds of H 2 0, 
forming CaO,H 2 0, or "slacked lime/' and expanding 
to several times its original size, with the evolution of 
much heat. CaO absorbs H 2 from the air, and then 
C0 2 , thus gradually becoming " air-slacked lime/' It is 
sparingly soluble in water. A thin film of calcium car- 
bonate will soon gather over a solution of lime exposed 
to the air. Water-lime contains a little clay and will 
harden under water. 

Uses. — Whitewash is a "milk of lime/' i. e., lime dif- 
fused through water. Concrete is a cement of coarse 
gravel and water-lime. It is of great durability. Hard 
finish is a kind of plaster in which gypsum is used to 
make the wall smooth and hard. Calcimine is a variety 
of whitewash made of whiting or plaster of Paris. Mor- 
tar is a mixture of lime and sand wet with H 2 0. It 
hardens rapidly, by absorbing C0 2 from the air to form 
a carbonate, and partly, perhaps, by uniting with the 
Si0 2 of the sand to form a silicate.* 

Lime is valuable as a fertilizer. It acts by rapidly de- 
composing all vegetable matter, and thus forming H 3 N 
for the use of plants, f It also sets free the alkalies 

* " If common mortar be protected from the air, it will remain without harden- 
ing fdr many years. It is stated that lime still in the condition of a hydrate has 
been found in the Pyramids of Egypt. When the ruins of the old castle of 
Landsberg were removed, a lime-pit, that must have been in existence three 
hundred years, was found in one of the vaults. The surface was carbonated to 
the depth of a few inches, but the lime below this was fresh as if just slacked, 
and was used in laying the foundations of the new building. "—American Cyclo- 
pedia. 

t If applied to a compost heap, it will set free H 3 N, thus robbing it of its 
most valuable constituent. This can be saved by sprinkling the pile with dilute 
H 2 S0 4 , or plaster, or by mixing it with dry muck, which will absorb the gas. 
If there is any copperas (produced by the oxidation of iron pyrites) in the soil, 
the lime will decompose it, forming gypsum and iron-rust, thus changing a 
noxious ingredient into an element of fertility. 



188 



IN OB GAN1C CHEMISTR Y. 



that are combined in the soil, and furnishes them to the 
plants, becoming itself a carbonate. Lime is also used 
extensively in the preparation of bleaching powder, in 
refining sugar, in making candles, in tanning, and in the 
manufacture of coal-gas. 



Fig. 56. 




A cave with stalactites and stalagmites. 



Calcitim Carbonate, CaC0 3 , includes limestone, 
chalk, marble, and marl, and forms the principal part of 
corals, shells, etc. H 2 charged with C0 2 dissolves 
CaC0 3 freely, which, when the gas escapes on exposure 
to the air, is deposited. In limestone regions, the water 
trickling down into caverns has formed "stalactites," 



CALCIUM. 189 

which depend from the ceiling, and " stalagmites/' that 
rise from the floor. These frequently assume curious 
and grotesque forms, as in the Mammoth Cave. Around 
many springs, the water, charged with CaC0 3 in solution, 
flows over moss or some vegetable substance, upon which 
the stone is deposited. The spongy rock thus formed is 
called calcareous tufa, or "petrified moss." (See Geology, 
p. 49.) Marble is crystallized limestone. Chalk or marl 
is a porous kind of limestone, formed from beds of shells, 
but not compressed as in common limestone. Whiting is 
ground chalk. 

Calcium Sulphate (CaS0 4 ,2H 2 0), Gypsum, Plas- 
ter, etc.* — This occurs as beautiful fibrous crystals in satin 
spar, as transparent plates in selenite, and as a snowy- 
white solid in alabaster. It is soft, and can be cut into 
rings, vases, etc. When heated it loses its water of crys- 
tallization, and is ground into powder, called " Plaster of 
Paris," from its abundance near that city. Made into a 
paste with H 2 0, it first swells up, and then immediately 
hardens into a solid mass. This property fits it for use 
in copying medals and statues, forming moulds, fastening 
metal tops on glass lamps, etc. Plaster (unburned or 
hydrated gypsum) is used as a fertilizer, f Its action is 
probably somewhat like that of lime, and in addition it 
gathers up ammonia and holds it for the plant. 



* The rational formula is CaO.S0 3 ; hence it is commonly called " sulphate of 
lime." Comparing the formula H 2 S0 4 and CaS0 4 , we see that one atom of Ca 
can replace two atoms of H ; it is therefore one of a class of elements called 
dyads (duo, two). An atom of K, as we have seen, can displace only one atom 
of H : it belongs to the monads (monos, alone). 

t It is said that Franklin brought CaS0 4 into use by sowing it over a field of 
grain on the hill-side, so as to form, in gigantic letters, the sentence, u Effects of 
gypsum." The rapid growth produced soon brought out the words in bold 
relief, and decided the destiny of gypsum among farmers. 



lJfi INORGANIC CHEMISTRY. 

Calcium Sulphite, CaS0 3 , should be distinguished 
from the sulphate. It is much used in preserving cider, 
being sold as " sulphite of lime." 

Calcium / P?wsp?iale, " Phosphate of Lime'' is fre- 
quently termed bone phosphate, as it is a constituent of 
bones. (See p. 120.) It is found in New Jersey, South 
Carolina,* and Canada. It is the valuable part of certain 
guanos. Fertilizers are prepared by treating ground 
bones with H 2 S0 4 , forming the so-called superphosphate 
of lime.f This is a mixture of gypsum and hydrogen 
calcium phosphate. The latter furnishes phosphorus to 
the growing plant to store in its seeds. — Example : corn, 
wheat. 



STRONTIUM AND BARIUM. 

These metals are very like Ca. The salts of Ba give a 
green tint to a flame and those of Sr a beautiful crimson ; 
and are hence much used in pyrotechny. Barium sul- 
phate, commonly called barytes, is found as a white min- 
eral, noted for its weight, whence it is often termed heavy 
spar. Indeed, the term barium is derived from a Greek 
word meaning heavy. This mineral is largely used for 
adulterating white-lead. BaCl 2 is a test for H 2 S0 4 . (See 
p. 117.) 

* Along the coast of South Carolina are millions of tons of rocks holding this 
important element of plant-food. The phosphatic beds extend over an area of 
several hundred square miles, and in some cases they are twelve feet thick. It 
is estimated that from 500 to 1000 tons underlie each acre.— Fireside Science. 

t Ca 3 2P0 4 (tricalcium phosphate) + 2H 2 S0 4 =H 4 Ca2P0 4 (acid phosphate or 
superphosphate) + 2CaS0 4 (calcium sulphate). As the gypsum is only slightly 
soluble in water, the superphosphate maybe removed from the mass by filtering, 
and used as a fertilizer, or be heated with charcoal to form phosphorus. In that 
case it is reconverted into tricalcium phosphate while a part of the phosphoric 
acid breaks up thus : 4H 3 P0 4 + 16C=P 4 +6H 2 +16CO. 



MAGNESIUM. HI 

MAGNESIUM.* 
Symbol, Mg Atomic Weight, 24,3 Specific Gravity, i.7, 

Source. — Mg is found in augite, hornblende, meer- 
schaum, soap-stone, talc, serpentine, dolomite, and other 
rocks. Its salts give the bitter taste to sea- water. When 
pure, it has a silvery lustre and appearance. It is very 
light and flexible. A thin ribbon of the metal will take 
fire from an ignited match, when it will burn with a 
brilliant white light, casting dense shadows through an 
ordinary flame, and depositing flakes of MgO. This light 
possesses the actinic or chemical principle so perfectly, 
that it is used for taking photographs at night, views of 
coal mines, interiors of dark churches, etc. It has every 
ray of the spectrum, and so does not, like gas-light, 
change some of the colors of an object upon which it 
falls. Magnesium lanterns are much used for purposes 
of illumination. By means of clockwork, the metal, in 
the form of a narrow ribbon, is fed in front of a concave 
mirror, at the focus of which it burns. It is hoped that 
the process of manufacture f may be cheapened, so that 
Mg may be furnished at a rate which will bring it within 
the scope of the arts. 

Compounds. — Magnesium Carbo?iale, MgC0 3 , 

* Mg is now usually classified with Zn, Cd, and In, since, while the metals of 
the alkaline earths decompose H 2 with avidity and set H free, these four act 
only upon steam at a red heat, being without effect upon H 2 at ordinary tem- 
peratures. Mg is treated here for convenience, while Zn is described among 
the common or useful metals. Cd and In are of no practical value. The oxide 
of Mg has a slight alkaline reaction, and until recently, Mg was considered one 
of the metals of the alkaline earths. 

t It is now prepared by heating MgCl a with metallic Na. 



Ui2 INORGANIC CHEMISTRY. 

is the "magnesia alba" or common magnesia of the drug- 
gist. Magnesium sulphate (MgS0 4 ,7H 2 0) is known as 
Epsom salt, from a celebrated spring in England in 
which it abounds. 



ATOMIC EQUIVALENCE* 

The Qua?tlivale?ice of an J?leme?il is its power 
of combining with H. Thus, if w^e examine the com- 
pounds HC1, H 2 0, H 3 N and H 4 C, we find the molecule 
of each has respectively 1, 2, 3, 4 atoms of H ; and we 
conclude that the elements CI, 0, N and C have differ- 
ent powers of combination whereby they can unite with a 
different number of H atoms. The same principle holds 
throughout all the elements. They are therefore divided 
into classes according to their power of combining with H, 
and are termed respectively, monatomic, diatomic, triatomic, 
&c, or monads, dyads, triads, &c. (Note, p. 139.) Each atom 
is supposed to have a certain number of bonds or more prob- 
ably poles, like those of a magnet, by which it holds or be- 
comes united to other atoms. H, Na, CI have but one bond 
or pole and can therefore, like all monads, only form pairs. 
lias two poles and can combine with H 2 , an atom of H at 
each pole, or with K 2 or HC1, or with an atom of some other 
dyad, as Zn. (Table, p. 288.) C has four poles and can unite 
with H 4 or Cl 4 , or 2 , or C1 2 or H 2 ; i. e. with four atoms 
of a monad, two of a dyad, or one of a dyad and tw T o of a 
monad. The quantivalence of an element is commonly 
represented thus,- CI 1 , O n . 

* For a full explanation of this subject see that delightful work Cooke's New 
Chemistry, Hoffman's Modern Chemistry or Wurtz's Introduction to Chemistry. 



ALUMINUM. 143 

METALS' OF THE EARTHS. 

Al, G, E, Y, Ce, La, D, 



ALUMINUM. 

Symbol, Al Atomic Weight, 27,5 Specific Gravity, 2,6. 

Source. — Al is named from alum, in which it occurs. 
It is also called the " clay metal." It is the metallic base 
of clay, mica, slate, and feldspar rocks. Next to and 
Si, it is probably the most abundant element of the earth's 
crust. It is a bright, silver- white metal ; does not oxidize 
in the air, nor tarnish by H 2 S. It gives a clear musical 
ring ; is only one-fourth as heavy as Ag ; is ductile, mal- 
leable, and tenacious. It readily dissolves in HC1, and in 
solutions of the alkalies, but with difficulty in HN0 3 and 
H0SO4. On account of its abundance (every clay-bank 
is a mine of it) and useful properties, it must ultimately 
come into common use in the arts and domestic life. 

Compounds.— Aluminum Oxide (A1 2 3 ).— Alumina, 
crystallized in nature, forms valuable Oriental gems. 
They are variously colored by the oxides ; — blue, in the 
sapphire ; green, in the emerald ; yellow, in the topaz ; 
red, in the ruby. Massive, impure alumina combined with 
magnetic iron, is called emery, and used for polishing. 

Aluminum Silicate (Al 2 3 ,2Si0 2 ), Silicate of 
Alumina, Common Clay. — When the clay rocks decay, 
by the .resistless and constant action of the air, rain, 
and frost, they crumble into soil. This contains clay, 
silica, and other impurities, such as lime, magnesia, 



m 



INOR GANIC CHEMISTR Y. 



oxide of iron, etc. The clay gives firmness to the soil, 
and retains moisture, but is cold and tardy- in producing 
vegetable growth. When free from Fe, it is used for 
making tobacco-pipes. When colored by ferric oxide, it 
is known as ochre, and is employed in painting. Com- 
mon stone and red earthen-ware are made from coarse 
varieties of clay; porcelain and china-ware require the 
purest material. Fire-bricks and crucibles, are made from 
a clay which contains much Si0 2 . Fullers' earth is a very 
porous kind, and by capillary attraction absorbs grease 
and oil from cloth. 

Glazing. — When any article of earthen-ware has 
been moulded from clay, it is baked. As the ware is 
porous, and will not hold H 2 0, 
a mixture of the coarse materials 
from which glass is made is then 
spread over the vessel, and heated 
till it melts and forms a glazing 
upon the clay. Ordinary stone- 
ware is glazed by simply throw- 
ing damp NaCl into the fur- 
nace. This volatilizes, and being 
decomposed by the hot clay makes 
a sodium silicate over the surface, 
while fumes of HC1 escape. Pb is 
sometimes used to give a yellowish 
glaze, which is very injurious, as 
it will dissolve in vinegar, and form sugar of lead, a 
deadly poison. The color of pottery- ware and brick is 
due to the oxide of iron present in the clay. Some varie- 
ties have no iron, and so form white ware and brick. 
Ahem is made by treating clay with H 2 S0 4 , forming 




Baking Porcelain. 



SPECTRUM ANALYSIS. IJfi 

an aluminum sulphate. On adding potassium sulphate 
a double salt is produced, which separates in beautiful 
octahedral crystals (Al 2 K 2 4:S04-f 24H 2 0). Instead of K 
an ammonium salt * is now generally added, and an am- 
monium alum made, which takes the place of the former 
in the market. f Alum is much used in dyeing. It 
unites with the coloring matter, and binds it to the fibres 
of the cloth. It is therefore called a mordant (mordeo, 
I bite). 



SPECTRUM ANALYSIS. 

Many of the metals named as rare have been recently 
discovered by what is termed Spectrum Analysis. We 
have already noticed that various metals impart a peculiar 
color to flame; thus Na gives a yellow tinge, copper a 
green, etc. If now we look at these colored flames 
through a prism, we shall find, instead of the "spec- 
trum " we are familiar with, a dark space strangely orna- 
mented with bright-tinted lines. Thus the spectrum of 
Na has one double, yellow line; J Ag, two green lines; 
Cs, a beautiful blue line. Each metal makes a distinc- 
tive spectrum, even when the flame is colored by several 
substances at once. This method of analysis is so deli- 



* Ammonium sulphate, from the ammoniacal liquor of the gas-works. (See 
page 83.) 

t There are a large number of other alums known, in which the isomorphous 
sesquioxides of iron, chromium, and manganese are substituted for the alumina 
in common alum : all these alums occur in regular octahedra, and cannot be sep- 
arated by crystallization when present in solution together. 

% The yellow, sodium line consists of two lines lying so closely together as to 
seem as one. They correspond to Fraunhofer's lines D (see Frontispiece, No. 2), 
as given in the drawings of Kirchhoff and Bunsen. 

7 



lJfi INORGANIC CHEMISTRY. 

cate that Ts3.vto.OTis of a grain of Na, or g^U^ of k 
can be detected in the flame of an alcohol lamp;* while a 
substance exposed to the air for a moment even will give 
the Na lines from the dust it gathers. L has thus been 
found to exist in tea, tobacco, milk, and blood, although 
in such minute quantities as to have eluded detection by 
former methods of analysis. 

PRACTICAL QUESTIONS. 

1. In the experiment with Na 2 S0 4 on page 133, an accurate ther- 
mometer will show that in making the solution, the temperature of 
the liquid will fall, and in its solidification, will rise. Explain. 

2. If, in making the solution of Na 2 S0 4 , we use the salt which 
has effloresced, and so become anhydrous, the temperature will 
rise instead of falling as before. Explain. 

3. Why is KN0 3 used instead of NaNO ;3 for making gunpowder? 

4. Why is a potassium salt preferable to a sodium one in glass- 
making ? 

5. What is the glassy slag so plentiful about a furnace ? 

6. State the formulae of nitre, saleratus, carbonate and bicarbonate 
of soda, plaster, pearlash, saltpetre, plaster of Paris, gypsum, car- 
bonate and bicarbonate of potash, sal-soda, and soda. 

7. Explain how ammonium carbonate is formed in the process 
of making coal-gas. 

8. Upon what fact depends the formation of stalactites ? 

9. Why is H F kept in gutta-percha bottles ? 

10. Explain the use of borax in softening hard water ? 

11. How are petrifactions formed ? 

12. In what part of the body, and in what forms, is phosphorus 
found ? 

13. Why are matches poisonous ? What is the antidote ? (See 
Physiology, page 209.) 

14. Will the burning phosphorus ignite the wood of the match ? 

* For the more perfect examination of the spectra, a " spectroscope " is used. 
This consists of a tube with a narrow slit at one end, which lets only a single 
ray ( f colored light fall upon the prism within, and at the other a small tele- 
scop ?, through which one can look in uponvthe prism and examine the spectrum 
of ai iy flame. (See Astronomy, page 285.) 



SPECTRUM ANALYSIS. 1^7 

15. What philosophical principle is illustrated in the ignition of 
a match by friction ? 

16. How much H 2 would bte required to dissolve a pound of 
KN0 3 ? 

17. What causes the bad odor after the discharge of a gun ? 

18. Write in parallel columns (see Question 54, page 96) the prop^ 
erties of common and of red phosphorus. 

19. What causes the difference between fine and coarse salt ? 

20. Why do the figures in a glass paper-weight look larger when 
seen from the top than from the bottom ? 

21. What is the difference between water-slacked and air-slacked 
lime? 

22. Why do oyster-shells on the grate of a coal-stove prevent the 
formation of clinkers ? 

23. How is lime-water made from oyster-shells ? 

24. Why do newly-plastered walls remain damp so long ? 

25. Will lime lose its beneficial effect upon a soil after frequent 
applications ? 

26. What causes plaster of Paris to harden again after being 
moistened ? 

27. What is the difference between sulphate and sulphite of 
lime? 

28. What two classes of rays are contained in the magnesium 
light ? 

29. What rare metals would become useful in the arts, if the 
process of manufacture were cheapened ? 

30. What is the rational formula for calcium carbonate ? Calcium 
sulphite V Calcium sulphate ? 

31. Why is lime placed in the bottom of a leach-tub ? 

32. Is saleratus a salt of K or of Na? 

33. Why will Na burst into a blaze when thrown on hot water? 

34. Why are certain kinds of brick white ? 

35. Illustrate the force of chemical affinity. 



U8 



1N0RGAJSTIC CHEMISTR Y. 



THE USEFUL METALS, 



IRON 



Symbol; Fe Atomic Weight, 56 Specific Gravity, 7.8, 

Irok is the symbol of civilization. Its value in the 
arts can be measured only by the progress of the present 
age. In its adaptations and employments it has kept 
pace with scientific discoveries and improvements, so that 
the uses of iron may readily indicate the advancement of 
a nation. It is worth more to the world than all the 
other metals combined. We could dispense with gold 
and silver — they largely minister to luxury and refine- 
ment, but iron represents solely the honest industry of 
labor. Its use is universal,* and it is fitted alike for mas- 
sive iron cables, and for screws so tiny that they can be 
seen only by the microscope, appearing to the naked eye 
like grains of black sand. 

Its abundance everywhere indicates how indispensable 
the Creator deemed it to the education and development 



* "Iron vessels cross the ocean, 
Iron engines give them motion, 
Iron needles northward veering, 
Iron tillers vessels steering, 
Iron pipe our gas delivers, 
Iron bridges span our rivers, 
Iron pens are used for writing, 
Iron ink our thoughts inditing, 
Iron stoves for cooking victuals, 
Iron ovens, pots, and kettles, 
Iron horses draw our loads, 
Iron rails compose our roads, 



Iron anchors hold in sands, 

Iron bolts and rods and bands, 

Iron houses, iron walls, 

Iron cannon, iron balls, 

Iron axes, knives, and chains, 

Iron augers, saws, and planes, 

Iron globules in our blood, 

Iron particles in food, 

Iron lightning-rods on spires, 

Iron telegraphic wires, 

Iron hammers, nails, and screws, 

Iron everything we use." 



IR ON. lJf.9 

of man. There is no " California " of iron. Each nation 
has its own supply. No other material is so enhanced in 
value by labor. 

1 lb. good iron is worth, say $ .04 

1" bar steel .17 

1 * inch-screws 1.00 

1 " steel wire 3 to 7.00 

1 " sewing-needles 14.00 

1 " fish-hooks 20 to 50.00 

1 " jewel- screws for watches 3,500.00 

1 " hair-springs for American watches .. . 16,000.00* 

Source. — Fe is rarely found native, i. e., in the metallic 
condition. Meteors, however, containing as high as 93 
per cent, of Fe associated with Ni and other metals, 
have fallen to the earth from space. Fe in combina- 
tion with various other substances is widely diffused. It 
is found in the ashes of plants and the blood f of animals. 
Many minerals contain it in considerable quantities. 
The ores from which it is extracted are generally oxides 
or carbonates. 

Preparation. — Sme2U?ig of Iro?i Ores. — Fe is 
locked up with O in an apparently useless stone. C is 
the key that is ready made and left for our use by the 
Creator. The process adopted at the mines is very sim- 
ple. A tall blast-furnace is constructed of stone and 
lined with fire-brick. At the top is the door, and at the 
bottom are pipes for forcing in hot air, sometimes twelve 



* One pound (Troy) of fine gold is worth in standard coin $248,062. All the 
above statements are based on careful and actual valuation. 

+ There are only about 100 grains of Fe in the blood of a rail-grown person—' 
about enough to make a ten-penny nail— yet it gives energy and life to the sys- 
tem. The metal is often administered as a tonic in the form of a fine powder, or 
a citrate of iron, and is a powerful remedy. 



ISO 



INOR G A NIC CHEMISTR T. 



thousand cubic feet per minute, by means of pistons 
driven by steam-power. The furnace, being filled with 



Fig. 59. 




A Blast-Furnace. 



limestone, coal and iron ore, in alternate layers, the fire 
is ignited. The C * unites with the of the ore, and 

* A little N sometimes unites with some C and K, forming potassium cyanide, 
or with Ti, if any is present, making beautiful copper-colored crystals of tita- 
nium cyanide. 



IRQ JV. 



151 



goes off as C0 2 . The CaC0 3 forms with the Si0 2 and 
other impurities a richly-col- 
ored glassy slag, which rises 
to the top. The melted Fe 
runs to the bottom, and is 
drawn off in channels cut in 
the sand on the floor of the 
furnace. The large main one 
is called the sow, and the 
smaller lateral ones the pigs, 
and hence the term pig-iron. 

Varieties of Fe. — The usual 
forms are cast, tvrought, and 
steel, depending upon the pro- 
portion of C which they con- 
tain. Cast-iron has from 2 to 
5 per cent., steel from 1 to 2 
per cent., and wrought-iron about J per cent. 

1. Cast Fe is the form which comes from the fur- 
nace. It is brittle, cannot be welded, and is neither 
malleable nor ductile. It is an exception to the law that 
" cold contracts," since at the instant of solidification it 
expands, so as to copy exactly every line of the mould into 
which it is poured. This fits it perfectly for castings. 
These may be made so soft as to be easily turned and 
filed, or so hard, by cooling in iron moulds,* that no 
tool will affect them, 

2. Wrought or Malleable Fe is made by burning 
the C from cast-iron, in a current of highly -heated air, in 
what is called a reverberatory furnace. The Fe is stirred 




Section of a Blast-Furnace. 



* These moulds are called u chills," and the iron is termed chilled iron. It is 
used for burglar-proof safes. 



152 



INOR GANIC CHEMISTR Y. 




A Reverberatory Furnace. 



constantly, and exposed to the heated air by means of 

long " puddling-sticks," as 
they are termed. It is taken 
out while white-hot and 
beaten under a trip-hammer 
to force out the slag; and 
lastly, pressed between groov- 
ed rollers to bring the parti- 
cles of Fe nearer each other 
and give it a fibrous struct- 
ure.* It is now malleable 
and ductile, and can be welded.f Fe is hardened by 
cooling rapidly, and softened by cooling slowly. The 
blacksmith tempers his work by plunging the article in 
cold H 2 0. 

3. Steel contains less C than cast, and more than 
wrought, iron. It is therefore made from the former by 
burning out a part of the C, and from the latter by heat- 
ing in boxes of charcoal, and so adding C.J The value 
of steel depends largely upon its temper. This is deter- 
mined by heating the article and then allowing it to cool. 
The higher the temperature the softer the steel. The 



* This fibrous structure is so noticeable that if a bar of the best Fe be notched 
with a chisel and then broken by a steady pressure, the fracture will present a 
stringy appearance, like that of a green stick. By constant jarring, however, Fe 
tends to take a crystalline structure, becoming rotten and brittle, so taat cannon, 
the axles of cars, etc, are condemned after a certain time, although no flaw may 
appear. 

+ It has been beaten into leaves so thin that they have been used for writing- 
paper— six hundred leaves being only half an inch in thickness— and has been 
drawn into wire as fine as a hair. 

% Cheap knives made of soft iron are often covered with a superficial coating 
of steel in this way. When we use such knives, we soon wear through this 
crust, and find metal beneath which will take no edge. This is termed case' 
hardening. 



IRON. 153 

workman decides this by watching the color of the oxide 
which forms on the surface.* Eazors require a straw yel- 
low ; table-knives, a purple ; springs and swords a bright 
blue; and saws a dark blue tint.f 

Sessemer' s (Process is now extensively used for 
making steel. Several tons of the best pig-iron are 
melted, and poured into a large crucible hung on 
pivots so as to be easily tilted. Hot air driven in from 
beneath, bubbles up through the liquid mass, producing 
an intense combustion. The roar of the blast, the hot, 
white flakes of slag ever and anon whirled upward, the 
long flame streaming out at the top, variegated by tints 
of different metals, and full of sparks of scintillating 
iron, all show the play of tremendous chemical forces. 
The operation lasts about twenty minutes, when the Fe 
is purified of its C and Si. Enough spiegel-eisen (look- 
ing-glass iron), an ore rich in C and Mn, is added to con- 
vert it into steel, when it is poured out and cast into 
ingots-J 

* The thin pellicles of iron-rust on standing H 2 produce a beautiful irides- 
cent appearance in the same way, the color changing with the thickness of the 
oxide. Just so a soap-bubble exhibits a play of variegated colors according to 
the thickness of the film in different parts. (See "Interference of Light," 
Physics, p. 168.) 

t These colors are removed in the subsequent processes of grinding and 
polishing, but they may be seen in a handful of old watch-springs, to be obtained 
of any jeweller. 

% In 1760, there lived at Attercliffe, near Sheffield, a watchmaker named 
Huntsman. He became dissatisfied with the watch-springs in use, and set him- 
self to the task of making them homogeneous. "If,' 1 thought he, "I can melt a 
piece of steel and cast it into an ingot, its composition should be the same 
throughout." He succeeded. His steel became famous, and Huntsman's ingots 
were in universal demand. He did not call them cast-steel. That was his 
secret. The process was wrapped in mystery by every means. The most faith- 
ful men were hired. The work was divided, large wages paid, and stringent 
oaths taken. One midwinter night, as the tall chimneys of the Attercliffe steel- 
works belched forth their smoke, a belated traveler knocked at the gate. It was 
bitter cold ; the snow fell fast ; and the wind howled across the moor. The 
stranger, apparently a common farm-laborer seeking shelter from the storm, 



15J/. IN OR GAN1C CHEMISTRY. 

Compounds. — 1. Black or Magnetic Oxide (Fe 3 4 ) is 
found in the loadstone, Swedish iron-ore, scales which fly 
off in forging iron, and in mines in various parts of the 
United States. It is the richest of the ores and contains 
as high as 72 per cent, of the metal. 2. Red Oxide 
of Iron, sesquioxide (ferric oxide, Fe 2 3 ), is seen in red 
iron-ore, in the beautiful radiated and fibrous speci- 
mens of hematite,* specular f iron, red ochre and chalk, 
bricks and pottery-ware. The sesquioxide, combining 
with H 2 0, forms — 3. Hydrated Sesquioxide of Iron (fer- 
ric hydrate, Fe 2 3 ,3H 2 0). This has a brown or yellow 
color, which changes to red by heat when the water is 
expelled, as in the burning of brick, pottery-ware, \ etc. 
These oxides generally give the brown, yellow, or red 
tints seen in sand, grayel, etc. The ferric oxide and 
hydrate are remarkable for the facility with which they 
absorb from the air, and impart it to other bodies. 
This is familiar in the rusting of nails in clap-boards, 
hinges in gate-posts, hooks in ropes, etc, etc. 

Iron Carbonate, FeC0 3 , is found as spathic § and 



awakened no suspicion. The foreman, scanning him closely, at last granted his 
request and let him in. Feigning to be worn-out with cold and fatigue, the poor 
fellow sank upon the floor and was soon seemingly fast asleep. That, however, 
was far from his intention. Through cautiously opened eyes, he caught glimpses 
of the mysterious process. He saw workmen cut bars of steel into bits, place 
them in crucibles, which were then thrust into the furnaces. The fires were urged 
to their utmost intensity until the steel melted. The workmen, clothed in rags, 
wet to protect them from the tremendous heat, drew forth the glowing crucibles 
and poured their contents into moulds. Huntsman's factory had nothing more 
to disclose. The secret of cast-steel was stolen. 

* Hcematites, blood-like, from the red color of its powder. 

t Speculum, a mirror, from the brilliant lustre of its steel-gray crystals and 
mica-like scales in micaceous iron-ore. 

% Clay, containing ferrous oxide (FeO), becomes red by its conversion into 
ferric oxide. 

§ Spath, spar, as some specimens consist of transparent, shiny crystals, hav- 
ing the same form as calcareous spar (calcium carbonate). 



IRON. 155 

clay Ironstone, and often contains some manganese,* 
which fits it for the manufacture of certain kinds of 
steel, whence it is termed steel-ore. In chalybeate springs, 
the free C0 2 in the water holds the FeC0 3 in solution. 
On coming to the air, the C0 2 escapes, and the Fe, ab- 
sorbing 0, is deposited as hydrated ferric oxide, forming 
the ochry deposit so common around such springs. 

Iron I)isulphide (FeS 2 ), Iron Pyrites, Fool's Gold 
— so called, because it is often mistaken by ignorant per- 
sons for Au. It occurs in cubical crystals and bright 
shiny scales. It can be easily tested by roasting on a hot 
shovel, when we shall catch the well-known odor of the 
S0 2 . FeS 2 is used as a source of S, and also in the 
manufacture of H 2 S0 4 . 

J^e?*rous Sulphate (FeS0 4 ,7H 2 0), Green Vitriol, 
Copperas, is made by the action of H 2 S0 4 on Fe, and, at 
Staiford, Connecticut, from FeS 2 , by exposure to air and 
moisture. It is used in dyeing, making ink, and in pho- 
tography. 

* Manganese is a hard, brittle metal, resembling cast-iron in its color and 
texture. It takes a beautiful polish. Its binoxide, the black oxide of manganese, 
is used in the manufacture of 0, CI, etc. By fusing Mn0 2 , KC10 :j , and KHO, a 
dark, green mass is obtained called "chameleon mineral.''' 1 It contains potas- 
sium manganate. If a piece of this be placed in H 2 0, the solution will undergo 
a beautiful change from green, through various shades, to purple. This is 
owing to the gradual formation of permanganic acid. The change may be pro- 
duced instantaneously by a drop of H 2 S0 4 . Potassium permanganate is remark- 
able for the facility with which it parts with its O, and thereby loses its color. 
It is used extensively as a disinfectant, and as a test of the presence of organic 
matter. (See page 60.) 



156 



INOR GANIC CHEMISTR Y. 



ZINC. 

Symbol, Zn. . . .Atomic Weight, 65 Specific Gravity, 7,15. 

Fusing Point, 773° F, 

Source. — Zn, or " spelter," as it is called in commerce, 
is found as ZnO, or red oxide, in New Jersey, and as ZnS, 
or zinc blende, in many places. 

Preparation. — ZnO is smelted on 
the same principle as iron ore, by 
heating with C. The reaction is 
as follows: ZnO + C = Zn + CO. 
Both these products distil, the 
Zn yapor being condensed while 
the CO gas escapes. 

Properties . — Zn is ordinarily 
brittle, but when heated to 200° 
or 300° F., it becomes malleable, 
and can be rolled out into the sheet 
Zn in common use. It burns in 
the air with a magnificent green 
light, forming flakes of ZnO, sometimes called "Philoso- 
pher's Wool."* When exposed to the air Zn soon oxi- 
dizes, and the thin film of white oxide formed oyer the 
surface protects it from further change. 

Uses. — Its economic uses are familiar. Sheet Fe 
dipped in melted Zn forms what is termed galvanized 
iron. Water-pipes made of this material are as unsafe 
as lead (see p. 160) until the Zn is entirely corroded. 

* Example : On a red-hot ladle, sprinkle some powdered saltpetre and Zn 
filings. The KN0 3 will furnish 0, and the metal will burn with great bril- 
liancy. 




Boasting Zinc Ore. 



TIN. 157 

The oxide and carbonate of zinc are rapidly formed, and 
these poisonous salts remain in the H 2 0. There is the 
same objection to metallic-lined ice-pitchers. Galvanic 
action between the metals promotes corrosion. H 2 
standing in reservoirs lined with Zn should, not be used 
for drinking purposes. In the case of zinc-covered roofs 
the rain-water contains zinc oxide.* 

Compounds. — ^z?ic Oxide, ZnO, is sold as zinc- 
white, and is valued as a paint, since it does not blacken 
by H 2 S like white-lead; but it is quite as hurtful to the 
painter. Zinc sulphate (ZnS0 4 ), white vitriol, is used in 
medicine. 



TIN. 

Symbol, Sn Atomic Weight, 118 Specific Gravity, 7,2, 

Fusing Point, 442° F, 

Source. — Sn, though one of the metals longest known 
to man, is found in but few localities. It is reduced from 
its binoxide by the action of C. 

Properties. — It is soft and not very ductile, but is quite 
malleable, so that tinfoil is not more than T ^ ^ of an inch 
in thickness. When quickly bent, it utters a shrill sound, 
called the " tin cry," caused by the crystals moving upon 
each other. Sn does not oxidize at ordinary temper- 
atures. Its tendency to crystallize is remarkable, f 

* When they were first introduced in Boston the washerwomen complained 
that the rain-water was hard, decomposed the soap, and made their hands 
crack. 

t Example : Heat a piece of Sn till the coating begins to melt ; then cool 
quickly in H 3 and clean in dilute aqua-regia. The surface will be found cov« 
ered with beautiful crystals of the metal. 



158 INORGANIC CHE MI STRY 

Uses. — Common sheet-tin is formed by dipping sheet- 
iron in melted Sn, which produces an artificial coating 
of the latter metal. If we leave H 2 in a tin dish, the 
yellow spots soon betray the presence of Fe. Pins made 
of brass wire are boiled with granulated tin, cream of 
tartar, and H 2 0, which give a bright white surface to 
the metal.* 



COPPER 



Symbol, Cu Atomic Weight, G3.5. . . .Specific Gravity, 8,9. 

Fusing Point, 1994° F. 

Source. — Cu is found native near Lake Superior, fre- 
quently in masses of great size. In these mines stone 
hammers have been discovered, the tools of a people older 
than the Indians, who probably occupied this continent, 
and worked the mines. In the western mounds, also, 
copper instruments are found. The sulphide, copper 
pyrites, is a well-known ore. Malachite (CuC0 3 ,CuO,H 2 0), 
the green carbonate, admits of a high polish, and is made 
into ornaments of exquisite beauty. 

Properties. — Cu is ductile, malleable, and an excellent 
conductor of heat and electricity. Its vapor gives a char- 
acteristic and beautiful green color to flame. It is har- 
dened by hammering, and softened by heating and plung- 
ing into cold H 2 0.f HN0 3 is the solvent of Cu. Its test 

* The pins are stuck in papers, as we see them, by machinery which picks 
them up out of a miscellaneous pile, counts them, and inserts them in the paper, 
ready for the market. The first part of the process is performed by a sort of 
coarse comb, which is thrust into the heap, and gathers up a pin in each of the 
spaces between the teeth. 

t The reverse of Fe, which fact ruins any theory we might form as to the cause 
in either case. 



LEAD. 159 

is H 3 N, forming in a solution an azure-blue precipitate, 
which dissolves in an excess of the reagent. 

Compounds.— Copper Acetate, Verdigris,* is pro- 
duced when we soak pickles in brass or copper kettles ; 
the green color which results is caused by this salt— a 
deadly poison. Preserved fruits, etc., should never stand 
in such vessels, as the vegetable acids dissolve Cu readily. 

Copper Oxide, CuO, is the black coating which 
collects on copper or brass kettles, and is very poisonous. 
It dissolves readily in fats and oils. Such utensils should 
therefore be used only when perfectly bright, and never 
with fruits, sweetmeats, jellies, pickles, etc. 

Copper Sulphate (CuS0 4 ,5H 2 0), Blue Vitriol, is 
much used in dyeing, calico printing, and galvanic bat- 
teries. 



LEAD 



Symbol, Pb Atomic Weight, 207. . . .Specific Gravity, 11. 3G. 

Fusing Point, 620° F. 

Source. — The most common ore of Pb is galena, PbS, 
which is reduced by roasting in a reverberatory furnace. 
The S burns and leaves the metal. 

Properties. — Pb is malleable, but contracts as it solidi- 
fies; so it cannot be used for castings. It is poisonous, 
though not immediately, as "bullets have been swallowed, 
and then thrown off without any harm except the fright." 
Its effects seem to accumulate in the system, and finally 

* The term verdigris is sometimes incorrectly applied to the green coating of 
carbonate, which gathers upon brass or copper in a damp atmosphere. 



160 INORGANIC CHEMISTRY. 

to manifest themselves in some disease. Persons who 
work in lead, as painters and plumbers, after a time suffer , 
with colics, paralysis, etc. 

Uses. — Pb is much used for water-pipes, and is the 
most convenient of any metal for that purpose. Pure 
H 2 passing through the pipe will not corrode the Pb, 
but the of the air it contains forms an oxide of 
lead which dissolves in the H 2 0, leaving a fresh surface 
for oxidation. If there are any sulphates or carbonates 
in the H 2 0, they will form a coating over the Pb, and 
protect it from further corrosion ; and as carbonate of 
lime is common in hard water, that is generally safe. If, 
when we examine a lead pipe that is in constant use, w T e 
find it covered with a white film, it is a good sign; but if 
it is bright, there is cause for alarm. Still, however much 
may be said upon the danger, people will use lead pipes, 
and the following precautions should be observed: Al- 
ivays let the water run long enough in the morning before 
using, to remove all which has remained in the water-pipes 
during the night ; and when the H 2 is let on again after 
it has been shut off for a while, leave the faucet open 
until the pipe is thoroughly tvashed. 

The Test of Pb is H 2 S, forming lead sulphide, PbS. 
The following is an interesting illustration: Thicken 
a solution of lead acetate with a little gum-arabic, so as 
not to flow too readily from the pen, and then make any 
sketch which your fancy may suggest. This, when dry, 
will be invisible. When it is to be used, dampen the 
paper slightly on the wrong side, and then direct 
against it a jet of H 2 S. The picture will at once blacken 
into distinctness. 

Compounds. — Tead Oxide, PbO, the well-known 



LEA D. 



161 



Fig. 63. 



litharge, is formed by heating Pb in a current of air.* 
It is used in glass-making, in paints, and in glazing 
earthenware. 

Lead "Dioxide \, Pb0 2 , is formed by oxidizing PbO. 
A mixture of the two, called minium or red-lead, is used 
for coloring sealing-wax red, and as a paint. 

Lead Carbonate, (PbC0 3 ), White-Lead. — This salt 
is made in large quantities in the following manner: 
Thousands of earthen pots fitted with covers 
and containing weak vinegar (acetic acid) 
and a small roll of Pb, are arranged in im- 
mense piles, and then covered with tan-bark. 
The acetic acid combines with the Pb, but 
the C0 2 formed by the decomposing tan- 
bark creeps in under the cover, driving off 
the acetic acid, and forming lead carbonate. 
The acetic acid, thus dispossessed, attacks 
another portion of the Pb, but is robbed 
again ; and so the process goes on, until at 
last the Pb is exhausted. White-lead is largely adulter- 
ated with heavy spar, gypsum, etc. 

Lead Acetate, Sugar of Lead, has a 
Fig. 6U. sweet, pleasant taste, but is a virulent poison. 
Its antidote is Epsom salt, which forms an 
insoluble lead sulphate. H 2 dissolves sugar 
of lead readily. If a piece of Zn, cut in small 
strips, be suspended in a bottle filled with a 
solution of lead acetate, the Pb will be depos- 
ited upon it by voltaic action in beautiful 
metallic spangles, forming the " lead-tree." 




A.— An 

pot. 

L.-A coil of lead. 

V. — A solution of 

vinegar. 




The Lead- 
tree. 



* Example : Heat a bit of lead upon charcoal in the oxidizing flame of the 
blow-pipe. A film of the suboxide forms first, then a yellow crust of the pro- 
toxide. 



162 I JS ORGANIC CHEMISTRY. 

THE NOBLE METALS. 

Ail, Ag, Pt, Hg, Pd J Irj Os, Ru, and Ro. 



GOLD 



Symbol, Au Atomic Weight, 197 Specific Gravity, 19,34, 

Fusing Point, about 2015° F, 

Sources. — Au is found sometimes in masses called nug- 
gets, but generally in scattered grains, or scales. As the 
rocks in which it occurs disintegrate by the action of the 
elements and form soil, the Au is gradually washed into 
the yalleys below, and thence into the streams and rivers, 
where, owing to its specific gravity, it settles and collects 
in the mud and gravel of their beds.* 

Preparation. — As the metal is thus found native, the 
process is purely mechanical, and consists simply in wash- 
ing out the dirt and gravel in wash-pans, rockers, sluices, f 
etc., at the bottom of which the Au accumulates. In the 
quartz-mills, the rock is thrown into troughs of water, 
where, by heavy stamps, the ore is crushed to powder. 

* In California, Au is found in the detritus (small particles of rock worn off by- 
attrition) of granite and quartz. It occurs in the gravel of hills from the surface 
to the tg bed-rock," sometimes a depth of 300 to 500 feet ; in the alluvial soil of 
the plains, and even in vegetable loam among the roots of grass. 

t Sluices are generally used in California. These are gently inclined troughs, 
sometimes extending for miles. Across the bottom are fastened low wooden 
bars, called riffles, above which quicksilver is placed. The dirt is shovelled into 
these sluices, or the auriferous hills are cut down, dissolved, and washed through 
them by powerful streams of water, which are constantly running. The H 2 
floats off the debris, while the Hg catches the gold. 



GOLD. 163 

As the thin liquid mud thus formed splashes up on either 
side, it runs over broad, metallic tables covered with Hg; 
or is washed through a fine wire-screen, and carried to 
the " amalgamating-pans " by a little stream of water. 
The Hg unites with the particles of Au and forms with 
them an amalgam (a compound of mercury and a metal). 
Au is easily separated from Hg by distillation,* and the 
latter collected to be used again. 

Quartation. — Au is commonly found alloyed with Ag. 
The Ag is then dissolved out by HN0 3 . There must be 
at least three parts of Ag to one of Au, else the gold will 
protect the silver from the action of the acid. If there 
is not so much, some is fused with the alloy, f 

Properties, — Pure Au is nearly as soft as Pb. It is ex- 
tremely malleable \ and ductile. Its solvent is aqua-regia. 
It does not oxidize at any temperature, and on account 
of its indestructibility, it was anciently called the king of 
the metals. 



* The larger part of the Hg is separated from the amalgam by pressure in can- 
vas or buckskin bags, the liquid Hg escaping through the pores, while the amal- 
gam is left quite dry. The latter is then " retorted " for distillation. 

t " In works for the refining of gold and silver, the processes can be conducted 
economically only when great care is taken to avoid the loss of any particles of 
the precious metals. Thus all the old crucibles are ground and treated with 
mercury, and after as much gold and silver as possible have been extracted, the 
residues are sold to the sweep-washers, who extract a little more by melting with 
lead. The very dust off the floors is collected and treated in a similar way.''' — 
Bloxam. 

$ For a description of the process of making gold-leaf, see Physics, page 20. 
" When one of these leaves is held up to the light, it exhibits a beautiful green 
color, and if it be rendered still thinner, either by beating, or by floating it upon 
a very weak solution of potassium cyanide, which slowly dissolves it, it trans- 
mits, when taken upon a glass plate and held up to the light, a blue, violet, or 
red light, in proportion as its thickness diminishes. Even when it is so trans- 
parent that one may read through it. the yellow color and lustre of the gold are 
still visible by reflected light. These varying colors of finely-divided gold are 
turned to account in the coloring of glass and in painting on porcelain." 



164 



INORGANIC CHE MI 



STM r. 



SILVER. 

Symbol, Ag. ... Atomic Weie-ht ins o •« „ 

weig Mj 1U8. . . .Specific Gravity, 10.5 
Fusing Point, 1873° F. 

bined with S as 12b ~?l * COmmo ^ however, com- 
' aS fe ^ <"*** Ag 2 S; with CI, forming 




Separation of Pb /w>™ a a- t a. *» 

J "jromAg. {See BloxarrCs Metals.) 



a Wltl1 Pb m ordinary galena. 



SI L V E R. 165 

Preparation. — 1st. The sulphide is refined as follows : 
The ore is crushed into fine powder and then roasted 
with common salt. The CI of the salt unites with the 
Ag, forming silver chloride. This is next put into a 
revolving cylinder with H 2 0, Hg, and iron scraps. The 
Fe removes the CI from the silver, when the Hg takes 
it up, thus forming an amalgam of Hg and Ag. From 
this the Ag is easily obtained, as in gold-washing.* 2d. 
From horn-silver, AgCl, the process is like the latter part 
of that just described. 3d. From lead the Ag can be pro- 
fitably obtained when there are only two or three ounces 
in a ton. The alloy of the two metals is melted and then 
slowly cooled. Pb solidifies much sooner than Ag, and 
by skimming out the crystals of Pb as fast as formed, 
it may be almost entirely separated. (See Fig. 65.) 

Cupellation. — A cupel (ciqiella, a M 66 

small cup) is a shallow vessel, made of 
bone-ashes. In this the Ag, debased with 
Pb and other impurities, is exposed to a 
red heat, so as to melt the metals, while a 

A Cupel. 

current of hot air plays upon the surface. 
The Pb oxidizes to PbO, and is absorbed by the porous 
cupel. The mass appears soiled and tarnished, but the 
refiner keeps his eye upon it as the process continues, 
watching eagerly, until at last there is a brilliant play of 
colors — he catches his own image in the perfect metallic 
mirror, and the little "button" of pure silver lies gleam- 

* The process of reducing silver ores at the West is unlike the German method 
given above, and varies in different localities. One plan is as follows: The 
powdered and roasted Ag 2 S is placed with Hg in iron pans, five feet in diameter 
and two feet deep. Here it is kept heated by steam to 180° and agitated by 
revolving stirrers. The chloride is not roasted, but is simply powdered, and 
then worked in the pans for an hour with NaCl before adding the Hg.— Ste- 
venson. 




166 



IN OR GANIC CHE 311 S T R Y. 



ing at the bottom.* This must now be immediately 
removed, or it will oxidize and waste, f 



Mg. 67. 




Cupels in Furnace. 

Properties. — Ag is the 'whitest of the metals. It is 
malleable and ductile. It expands at the moment of 
solidification, and, therefore, can be cast. It has a power- 



* See Malachi iii. 3. 

t During the cooling of the cake of Ag, some very remarkable phenomena are 
observed. When a thin crust of metal has formed upon the surface, the Ag be- 
neath it assumes the appearance of boiling, and the crust is forced up into hollow 
cones about an inch high, through which the melted Ag is thrown out with ex- 
plosive violence, some of it being splashed against the arch of the furnace, and 
some solidifying into most fantastic tree-like forms several inches in height. 
This behavior of Ag has been shown to be due to its property of mechanically 
absorbing O, at a temperature above its melting-point, which it gives off as it ao- 
proaches the point of solidification, the escaping gas forcing up the crust of solid 
Ag formed upon the surface. 



SIL VEB. 167 

ful attraction for S, forming silver sulphide.* Silver 
spoons and door-knobs are tarnished by the minute quan- 
tities of H 2 S present in the air.f The best solvent of Ag 
is HN0 3 . The test of Ag in solution is HC1, which forms 
a cloudy precipitate of silver chloride. A solution of silver 
coin is blue, from the Cu it contains. Standard silver is 
whitened by being heated until the of the air has con- 
verted a little of the Cu on the outside into CuO, which is 
dissolved by immersing in dilute H 2 S0 4 or H 3 N. The 
film of nearly pure Ag which then remains at the surface 
exhibits a want of lustre and is called dead or frosted sil- 
ver. It is brightened by burnishing. 

Compounds, — Silver Nitrate, AgN0 3 , is sold in 
small, round sticks as lunar caustic, used as a cautery. It 
stains the skin and all organic matter black, especially 
when exposed to the light, owing to . the formation of 
silver oxide, Ag 2 O.J Hair-dyes and indelible inks con- 
tain AgN0 3 . It is also the basis of photography (light- 
drawing) and daguerreotyping,§ which are both founded 



* The perspiration from our bodies contains more or less S, and this, as it 
passes through our pockets, combines with any silver we may chance to have 
there. 

t Those who have visited sulphur springs know the propriety of carefully pro- 
tecting their watches, and of never wearing gold ornaments to the hot baths. 
Ag 2 S is very easily dissolved by a little dilute ammonia (1 part of HN 3 to 20 of 
H 2 0), which is therefore used for cleaning silver door-knobs.— Oxidized silver, 
as it is erroneously called, is made by immersing articles of silver in a solution 
obtained by boiling sulphur with potash, when the metal becomes coated with a 
thin film of sulphuret of silver.— Bloxam. 

X A very pretty experiment, illustrating the formation of this oxide, is per- 
formed by dropping into a test-tube of H 2 a few drops of silver nitrate in solu- 
tion, and then adding potash, when a copious precipitate of the brown hydrate of 
Ag 2 will fill the tube. Now put in a little H 3 N, which will instantly dissolve 
the silver oxide, and leave the liquid as clear and sparkling as spring-water.— 
The stain of silver nitrate may be removed by a strong solution of potassium 
iodide or the poisonous potassium cyanide. 

§ The daguerreotype is named from M. Daguerre, the discoverer, who received 
a pension of 6,000 francs per year from the French government. A plate of Cn, 



168 IXORGAKIC CHEMISTRY. 

upon essentially the same principles. The general out- 
lines of the photographic process are as . follows : 1. 
Iodized collodion* is poured upon a clean glass plate, 
which, on evaporation, it covers with a transparent film. 
2. The plate is put in the " nitrate of silver bath/' f where 
the salt of silver is absorbed by the collodion film and 
changed to brom-iodide of silver. The plate is now ready 
for the picture. After the sitting, the plate is taken, 
carefully protected from the light, to the operator's room. 
Here the picture is, 3, developed by a solution of ferrous 
sulphate (protosulphate of iron) or pyrogallic acid (see p. 
212) : at the right stage the liquid is washed off, and the 
operation checked. 4. It is fixed with a solution of so- 
dium hyposulphite, which dissolves the unaltered brom- 
iodide of silver. 5. It is washed, dried, and coated with 
amber varnish to preserve the film from accidental injury. 
The "negative" is now completed, and is a correct like- 

plated on one side with Ag, is exposed to the vapor of I and Br until a compound 
of brom-iodide of silver is formed upon the surface. This is extremely sensitive 
to the light, hence the process is always conducted in a dark closet. The plate is 
then quickly carried, carefully covered, to the camera, and placed in the focus, 
where the rays of light from the person whose "picture is being taken" fall 
directly upon it. These rays decompose the brom-iodide of silver. The amount of 
this change is directly proportional to the number of rays that are reflected from 
different parts of the person to form the image in the camera. A white garment 
reflects all the light that falls upon it, so the corresponding part of the plate will 
be very much changed. A black garment reflects no light, so that part will not 
be changed at all. The different colors and shades reflect varying proportions of 
light, and so influence the plate correspoDdingly. When the plate is taken out 
of the camera, it is carefully covered again and carried quickly into the dark 
closet. No change can be detected by the eye ; but on exposure to the vapor 
of Hg, wherever the Ag has been freed, the Hg will combine with it, forming a 
whitish amalgam, but it has no effect on the rest of the plate. The picture thus 
treated comes forth nearly perfect in its lights and shades. The undecomposed 
brom-iodide of silver is removed by a solution of sodium hyposulphite. A solu- 
tion of gold chloride and sodium hyposulphite is then poured upon the plate and 
warmed. This golden varnish finishes the picture. 

* Iodized collodion is composed of gun-cotton dissolved in alcohol and ether, 
to which are added ammonium iodide and cadmium bromide, or similar salts. 

t The nitrate of silver bath contains nitrate of silver and iodide of silver in 
solution, and is acidulated with nitric acid. 



PLATINUM. 169 

ness, only the lights and shades are reversed. From this 
the pictures are, 1, "printed" by placing the negative 
upon a sheet of prepared paper,* and exposing it to the 
sun's rays. When the colors are sufficiently deepened, 
the picture is, 2, toned in the " toning-bath," which con- 
tains a little " bicarbonate of soda " and a minute quan- 
tity of gold chloride ; 3, fixed, by sodium hyposulphite 
which dissolves the unaltered AgCl ; 4, thoroughly 
washed in water frequently renewed ; and, lastly, dried 
and mounted on card-board. The thoroughness of the 
third and fourth processes has much to do with the per- 
manence of the picture. If any of the chloride or the 
compound formed by the hyposulphite be left, it will 
cause fading or discoloration. 



PLATINUM 



Symbol, Pt. . . .Atomic Weight, 197. . . .Specific Gravity, 21,53. 
Fusing Point, about 4591° F, (?) 

Source. — Pt f is chiefly found in the Ural Mountains, 
where it occurs in alluvial deposits, usually in small, 
flattened grains. \ 

Preparation. — The "ore,? as it is called, is separated 
from the earthy particles by washing. The grains of Pt re- 
main behind with particles of Au, Fe 3 4 , and an alloy of Os 
and I r. § The Au is removed by amalgamation, and the Fe 

* This paper is " sensitized " by floating it on a solution of sodium chloride, 
and then on one of silver nitrate, thus filling the pores of the paper with the 
silver chloride, which is extremely sensitive to light. 

t The word platinum signifies " little silver. 11 

X The largest nugget ever found weighed 18 lbs. 

§ Ir is named from Iris, the rainbow, because of the beautiful color of its salts 

8 



170 INORGANIC CHEMISTRY. 

by a magnet The Pt is then dissolved by melted Pb and 
afterward recovered from this alloy by cupellation. 

Properties. — Pt resembles Ag in its appearance. It is 
one of the most ductile metals, wire being made from it 
so fine as to be invisible to the naked eye. * It is soluble 
in aqua-regia, but not in the simple acids. It does not 
oxidize in the air, is the most infusible of metals, and can 
be melted only by the heat of the compound blow-pipe 
or voltaic battery. In the arts it is fused in the former 
manner. These properties fit it for use as crucibles, and 
for this purpose it is invaluable to the chemist. 



MERCURY 



Symbol, Hg. . . .Atomic Weight, 200. . . .Specific Gravity, 13,5, 
Melting (Freezing) Point,- 39°F. . .Boiling Point, 662° F. 

Mercury is also called quicksilver, because it runs 
about as if it were alive, and was supposed by the alche- 
mists to contain silver. It was known very anciently, 
and the mines of Spain were worked by the Eomans. 

Source. — Cimiabar, HgS, a brilliant red ore, is the 
principal source of this metal, f When sublimed with S, 
Hg forms the pigment known as "vermilion." 

in solution. When combined with Os, it makes " iridosmine, ,, used for the nibi 
of gold pens. 

* Wollaston's Method, as it is called, consists in covering fine platinum wire 
with several times its weight of Ag, and then drawing this through the plates 
used for drawing wire until the finest hole is reached, when the wire is placed 
in HN0 3 , which dissolves the Ag and leaves the Pt intact. This, in the form of 
the finest wire known, may be found in the solution by means of a microscope. 
(See Physics, p. 19.) 

t Hg is found native in Mexico in very small quantities, where the mines are 
said to have been discovered by a slave, who, in climbing a mountain, came to 
a very steep ascent. To aid him in surmounting this, he tried to draw himself 



ME R c v r r. 171 

Preparation. — Hg is readily prepared by roasting HgS 
in the open air. The S passes off as S0 2? while the Hg 
volatilizes and is condensed in earthen pipes. 

Properties. — Hg emits a vapor at all temperatures above 
40° F. Its solvent is H N0 3 . It forms an amalgam * with 
gold or silver. This is its most singular property. A 
gold leaf dropped upon mercury disappears like a snow- 
flake in water. Particles of Ag or Au ? too fine to be seen 
by the eye, will be found by Hg and gathered from a 
mass of ore. 

Uses. — Hg is extensively employed in the manufacture 
of thermometers and barometers; for silvering mirrors; f 
and for extracting the precious metals from their ores. 

lip by a bush which grew in a crevice above. The shrub, however, giving way, 
was torn up by the roots, and a tiny stream, of what seemed liquid silver, trick- 
led down upon him. 

* " Several years ago, wmile lecturing upon chemistry before a class of ladies, 
we had occasion to purify some quicksilver by forcing it through chamois skin. 
The scrap of leather remained upon the table after the lecture, and an old lady, 
thinking it would be very nice to wrap her gold spectacles in, accordingly appro- 
priated it to this purpose. The next morning she came to us in great alarm, 
stating that the gold had mysteriously disappeared, and nothing was left in the 
parcel but the glasses. Sure enough, the metal remaining in the pores of the 
leather had amalgamated w r ith the gold, and, entering, destroyed the spectacles. 
It was a mystery, however, which we could never explain to her satisfaction."— 
J. R. Nichols in Fireside Science. 

t Mirrors were anciently made of steel or silver, highly polished. They were 
very liable to rust and tarnish, and so a piece of sponge, sprinkled with pum- 
ice-stone, was suspended from the handle for rubbing the mirror before use. 
Seneca, in lamenting over the extravagance of his time among the old Romans, 
says : "Every young woman now-a-days must have a silver mirror." The pro- 
cess of silvering ordinary mirrors is briefly as follows : Tin-foil is first spread 
evenly upon a marble table, and then the Hg is carefully poured over it. The 
two metals combine, forming a bright amalgam. A clean, dry plate of glass is 
then carefully pushed forward over the table so as to carry the superfluous Hg 
before it, and also prevent the air from getting between the glass and the amal- 
gam. Weights are afterwards added to cause the film to cling more closely. In 
twenty-four hours the plate is removed, and in three or four weeks is dry enough 
to be framed. When we look in a mirror we rarely realize what, it has cost 
others to thus minister to our comfort. The workmen are short-lived. A paral- 
ysis sometimes attacks them within a few weeks after they enter the manufac- 
tory, and it is thought remarkable if a man escapes for a year or two. Its effects 
are similar to those of calomel ; the patient dances instead of walking, and can- 
not direct the motion of his arms, nor in some cases even masticate his food. 



172 INORGANIC CHEMISTRY. 

The action of Hg on the human system is too well 
known to need description. " In its metallic state, Hg 
has been taken with impunity in quantities of a pound 
weight " {American Cyclopedia), but when finely divided, 
as in vapor, mercurial ointment,* or " blue-pill," its effects 
are marked. It renders the patient extremely susceptible 
to colds ; acts, as is generally thought, upon the liver, in- 
creasing the secretion of bile, and repeated doses pro- 
duce "salivation." 

Compounds. — Mercuric Oxide, HgO, "red preci- 
pitate," is interesting, as the substance from which 
Priestley discovered gas. 

Mercurous Chloride, HgCl, Calomel, is a white 
powder used in medicine. It can be easily distinguished 
from corrosive sublimate, since it is insoluble in H 2 0, 
and hence, tasteless. 

Mercuric Chloride, HgCl 2 , Corrosive Sublimate, is 
a heavy, white solid, soluble in H 2 0, and with a burning 
metallic taste. It has powerful antiseptic properties, and 
is used to preserve specimens in natural history. It is a 
deadly poison. Its antidote is white of eggs, milk, etc. 



THE ALLOYS. 

These are very numerous, and many of them possess 
properties so different from their elements that they 
almost seem like new metals. The color and hardness 
are changed, and sometimes the melting point is below 

* This is vulgarly called "anguintum," which may be a corruption of the 
Latin term unguentum (unguent). It is used in cutaneous diseases. 



THE ALL YS. 173 

that of any one of the constituents. The proportions of 
the metals used vary. The following is a fair average : 

Type-metal contains 3 parts of lead * to 1 of anti- 
mony, f 

*Pewler contains 4 parts of Sn and 1 of Pb. 

Britannia consists of 100 parts of Sn, 8 of Sb, 2 of 
Bi ? I and 2 of Cu. 

!B?*ass is 2 parts of Cu and 1 of Zn. 

Germa?i Silver contains Cu, Zn, and N i § (brass 
whitened by nickel). 

Soft Solder, used by tinsmiths, is made by melting 
Pb and Sn together, the usual proportion being half-and- 
half. 

Hard Solder is composed of Cu and Zn. 

JFtisible Jlfelal melts at 201°, and spoons made of 
it will fuse in hot tea. It can be melted in a paper-cru- 
cible over a candle. It consists of Bi, Pb, and Sn. Yet 



* An improved kind lately introduced is 2 parts Pb, 1 part Sn, and 1 Sb. 

+ Antimony was discovered by Basil Valentine, a monk of Germany, in the 
fifteenth century. It is said that, to test its properties, he first fed it to the 
swine kept at the convent, and found that they thrived upon it. He then tried it 
upon his fellow-monks, but perceiving that they died in consequence, he forth- 
with named the new metal, in honor of this fact, anti-nwine (anti-monk), whence 
our term antimony is derived. It is a brittle, bluish-white metal, with a beau- 
tiful laminated, star-like, crystalline structure. It is used simply as an alloy for 
type-metal, Britannia-ware, etc. Its test is H 2 S, which throws down a brilliant 
orange-colored precipitate. Melt a small fragment of Sb before the blow-pipe, 
and throw the melted globule upon an inclined plane. It will instantly dart off 
in minute spheres, each followed by a long trail of smoke. 

* Bismuth is a reddish-white metal used only in alloys and in the construction 
of thermo-electric piles. (See Physics, p. 249.) 

§ Ni, like Co, is a constituent of meteorites. It is mined in Pennsylvania for 
the United States government to make into cents. Formerly its principal use was 
in German silver, but of late it has been employed extensively in the manufac- 
ture of the best plated-ware. (See Physics, p. 238.) Its silvery whiteness, when 
pure, its high polish, which often lasts for years, and its hardness, almost equal 
to that of steel, eminently fit it for the plating of mathematical and other delicate 
instruments. The salts of Ni have a handsome green tint. The rare gem chryso- 
prase is colored by the oxide. 



17 Jf INORGANIC CHEMISTRY. 

the first metal melts at 507°, the second at 617°, and the 
third at 442°. 

jB?*onze is 95 parts of Cu, 4 of Sn, and 1 of Zn. - 

Gold is soldered with an alloy of itself and Ag ; Sil- 
ver, with itself and Cu ; Copper, with itself and Zn : 
the principle being that the metal of lower fusing point 
causes the other to melt more easily. 

Coin . — The precious metals, when pure, are too soft 
for common use. They are therefore hardened by other 
metals. The gold coin of the United States consists of 9 
parts of gold and 1 of alloy. The alloy is composed of 9 
parts of Cu, whitened by 1 of Ag, so as not to darken the 
gold coin. Silver coin is 9 parts of Ag and 1 of Cu. The 
nickel cent is 88 parts of Cu and 12 of Ni. Cu being- 
cheaper than Ni, it is used to make the coin larger. 
The term carat, applied to the precious metals, means 
-^4 part. Therefore, gold 18 carats fine, contains J-f of 
gold and fa of alloy. 

Shot is an alloy of about 1 part of As to 100 of Pb. 
The manufacture is carried on in what are called " shot- 
towers," some of which are two hundred and fifty feet 
high. The alloy is melted at the top of the building, 
and poured through colanders. The metal, in falling, 
breaks up into drops, which take the spherical form (see 
Physics, jmges 44 and 192), harden, and are caught at 
the bottom in a well of water which cools the shot and 
also prevents their being bruised in striking. The shot 
are dipped out, dried, and then assorted, by sifting in a 
revolving cylinder, which is set slightly inclined and per- 
forated with holes, increasing in size from the top to the 
bottom. The shot being poured in at the top, the small 
ones drop through first, next the larger, and so on, til] 



PROPERTIES OF THE METALS. 175 

the largest reach the bottom. Each size is received in its 
own box. Shot are polished by being agitated for several 
hours with black-lead, in a rapidly revolving wheel. 
They are finally tested by rolling them down a series 
of inclined planes placed at a little distance from each 
other. The spherical shot will jump from one plane to 
the next, while the imperfect ones will fall short, and 
drop below ; or sometimes, by rolling down a single in- 
clined plane, the spherical ones will go to the bottom, 
while the imperfect ones roll off at the sides. 

Oreide is a beautiful alloy of brass resembling gold, 
but it soon tarnishes by exposure to the air. 

Aluminum !Bronze> or gold, is an alloy of Al and 
Cu. It is elastic, malleable, and very light. It strikingly 
resembles gold, and is much used instead of that costly 
metal. 



REVIEW OF THE PROPERTIES 
OF THE METALS. 

Oxidation. — K and Na have an intense attraction 
for 0, while Au and Ag have little affinity for it, and are 
therefore found native. 

"Density. — L is the lightest liquid known. Pt is 
the heaviest solid, being over twenty-one times as heavy 
as H 2 0, while K and Na will float upon it. 

Melting "Point. — Hg is liquid at all ordinary tem- 
peratures. K and Na melt beneath the boiling point of 
H 2 ; Zn below a red heat, and Cu above ; Co, Ni, and 
wrought-iron require the greatest heat of the forge 
(4000°), while Pt and Os melt only in the flame of the 



17b' INORGANIC CHEMISTRY. 

oxy-hydrogen blow-pipe. Sn melts at the lowest temper- 
ature (442°) of any of the ordinary metals. 

Color. — The most common color is white, of varying 
shades. It is nearly pure in Ag, Pt, Cd, and Mg; yellow- 
ish in Sn ; bluish in Zn and Pb; gray in Fe, and reddish 
in Bi. Cu is a full red, and Au a bright yellow. 

Malleability '. — Au, Ag, and Cu are the most malle- 
able of the metals ; Au, Ag, and Pt are the most ductile. 

!Brillleness . — Sb and Bi may be easily powdered ; 
Zn may be broken with more difficulty, while the fibrous 
metals are exceedingly tough. 

Tenacity. — Steel is the most, and lead the least, 
tenacious of the metals; the proportion being as 1 to 42. 

Special ^Properties . — Certain of the metals are 
valuable because of their peculiar properties. Thus, Hg, 
because it will form an amalgam, and is a liquid at all ordi- 
nary temperatures ; Sb, because it hardens Pb and Sn ; Bi 
and Cd, because they render Pb and Sn more easily melted ; 
Ni, because it whitens Cu; Mg, for its brilliant light; 
Au, for its rarity and lustre ; Fe, for the diverse properties 
it can assume in wrought and cast iron, and in steel, and 
because it is the only metal which can be used for the 
magnetic needle and electro-magnet; Cu, for its duc- 
tility and its conductibility of electricity ; and Pt, for its 
infusibility. 

PRACTICAL QUESTIONS. 

1. Pb is softer than Fe ; why is it not more malleable ? 

2. What is the cause of the changing color often seen in the 
scum on standing water ? 

3. How can the spectra of the metals be obtained ? 

4. Ought cannon, car-axles, etc., to be used until they break or 
wear out ? 



PRACTICAL QUESTIONS. 177 

5. Why is " chilled iron " used for safes ? 

6. Doe's a blacksmith plunge his work into water merely to 
cool it ? 

7. What causes the white coating made when we spill water 
on zinc? 

8. Is it well to scald pickles, make sweetmeats, or fry cakes in 
a brass kettle ? 

9. What danger is there in the use of lead pipes ? Is a lining 
of Zn or Sn a protection ? 

10. Is water which has stood in a metal-lined ice-pitcher health- 
ful ? 

11. If you ask for " cobalt " at a drug-store, what will you get ? 
If for " arsenic ?" 

12. What two elements are fluid at ordinary temperatures ? 

13. Should we touch a gold ring to mercury ? * 

14. Why does silver blacken if handled ? 

15. Why does silver tarnish rapidly where coal is used for fires ? 

16. Why is a solution of a silver coin blue ? 

17. Why will a solution of silver nitrate curdle brine ? 

18. Why does writing with indelible ink turn black when exposed 
to the sun, or to a hot iron ? 

19. What alloys resemble gold ? 

20. Why does a fish-hook " rust out " the line to which it is fas- 
tened ? 

21. Why do the nails in clap-boards loosen ? 

22. Show, that the earth's crust is mainly composed of burnt 
metals. 

23. What kind of iron is used for a magnet ? For a magnetic 
needle ? 

24. Why does a tin pail so quickly rust out when once the tin is 
worn through ? 

25. Why is the zinc oxide found in New Jersey red, when zinc 
rust is white V 

26. Should we filter a solution of permanganate of potash 
through paper ? 

27. Why is wood, cordage, etc., sometimes soaked in a solution 
of corrosive sublimate ? 



* If the surface is only whitened, the Hg may be removed with dilute HN0 3 , 
and the ring he polished to look as before. The Hg will soon penetrate the gol(J 
and render it brittle. 



178 INORGANIC CHEMISTRY. 

28. Why does the white paint around a sink turn black ? 

29. Why is aluminum, rather than platinum, used for making 
the smallest weights ? 

30. How would you detect the presence of iron particles in black 
sand ? 

31. Which metals can be welded ? 

32. When the glassy slag from a blast-furnace has a dark color, 
what does it show? 

33. In welding iron the surfaces to be joined are sometimes 
sprinkled with sand. Explain. 

34. What is the difference between an alloy and an amalgam ? 

35. Steel articles are blued to protect from rusting, by heating in 
a sand-bath. Explain. 

36. Give the rational formulae for copperas and white lead. 

37. Why is Hg used for filling thermometers ? 

38. What oxide is formed by the combustion of Na, K, Zn, S, Fe, 
Pb, Cu, P, etc.? Which are bases? Acids? Give the common 
name of each. 

39. Is charcoal lighter than H 2 ? 

40. Name the vitriols. 

41. Is Mg a monad or a dyad? Zn ? 

42. Name some dibasic acid. 

43. Name a neutral salt. An acid salt. 

44. Calculate the percentage of water contained in crystallized 
copper sulphate. Sodium sulphate. Calcium sulphate. Alum. 

45. What is the test for kg ? Cu ? 

46. What weight of crystallized "tin salts" (SnCl 2 ,2H 2 0) can be 
prepared from one ton of metallic tin ? 

47. 100 parts by weight of silver yield 132.8 + parts of silver 
chloride. Given the combining weight of chlorine, required that 
of silver. 

48. What is the composition of slaked lime ? 

49. How is ferrous sulphate obtained ? How many tons of crys- 
tals can be obtained by the slow oxidation of 230 tons of iron 
pyrites containing 37.5 per cent, of sulphur ? 

50. Required 500 tons of soda crystals ; what will be the weight 
of salt and pure sulphuric acid needed ? 

51. Describe the uses of lime in agriculture. 

52. How many tons of oil of vitriol, containing 70 per cent, of 
pure acid (H. 2 S0 4 ), can be prepared from 250 tons of iron pyrites, 
containing 42 per cent, of sulphur ? 



III. 

iDrganic Chemistry, 



" Thus the Seer, 
With vision clear, 
Sees forms appear and disappear, 
In the perpetual round of strange, 
Mysterious change 

From birth to death, from death to birth, 
From earth to -heaven, from heaven to earth ; 
Till glimpses more sublime 
Of things, unseen before, 
Unto his wondering eyes reveal 
The Universe as an immeasurable wheel 
Turning forevermore 
la the rapid and rushing river of Time." 

Longfellow 



ORGANIC CHEMISTRY, 



INTRODUCTION. 

Necessity of Organization. — We have thus far 
spoken of the various elements of matter. We have 
found many which are necessary to the growth of our 
bodies, but still we cannot live upon them. We need 
phosphorus, but we cannot eat it, for it is a deadly poison. 
We need Fe, but it would make a most unsavory diet. 
We need CaO, but it would corrode our flesh. We need 
H, but it must be combined with as H 2 to be of 
any value to us. We need C, but charcoal would form a 
very indigestible food. If we were shut up in a room 
with all the elements of nature, we not only could not 
combine them so as to produce those organic substances 
necessary to our life and comfort, but we should actually 
die of starvation. We thus find that the mineral matter 
must be organized in some manner before we can use it 
to advantage. 

"Plants Organize Matter. — We have seen that 
in the plant the sunbeam decomposes the poisonous C0 2 
and furnishes us the life-giving ; that we cannot create 
force ourselves, or draw it direct from the sun, but must 
take that which the plant has hoarded for us. We shall 



182 ORGANIC C HE 311 S TRY. 

now find that, in addition, the plant changes inorganic 
matter to organic. It takes up the elements we need for 
our growth and for use in the arts, and combines them 
into plant-products, such as wood, starch, sugar, etc. — 
We are thus dependent upon the vegetable world for the 
grand staples of commerce and of luxury — all that we 
eat, drink, or wear. Each tiny leaf, every tree and shrub, 
every spire of grass even, is working constantly for us. 
The earth was once a burnt body — the cinders of the vast 
fire amid which it had its origin. (See Geology, page 17.) 
Every organized substance now on its surface has been 
rescued from the grasp of by the plants. 

'Diffe?*e?ice belwee?i Orga?iic a?id Znorga?iic 
Bodies. — 1- While inorganic bodies deal with sixty- 
three elements, organic are composed principally of only 
four, C, H, 0, and N. As C is their characteristic ele- 
ment, they are frequently styled the " carbon compounds." 
2. While inorganic molecules consist of only a few atoms, 
and are therefore very simple in their construction, as : 
H 2 0, C0 2 , K 2 0, organic frequently contain a large num- 
ber, and are extremely complex, as: Sugar = C| 2 H 22 0||, 
having 45 atoms in a molecule; stearin = C 57 H,, 6 , 
having 173 atoms; albumen = C 72 H|, N| 8 S0 22 , having 
222 atoms, and even more, according to some author- 
ities. 3. While inorganic bodies are formed and re- 
main fixed in one state under the influence of chemical 
affinity, organic grow rapidly, change constantly, and 
when life ceases, as rapidly decay, and are transformed 
into inorganic substances. 4. Owing to their complex 
structure, and the presence in many of them of the nega- 
tive N, they form most unstable compounds. In this we 
find the cause of their quick decay. The vital principle 



ALLOTROPISM. 18 & 

alone holds them together, frequently in opposition to 
the laws of chemical affinity ; and the instant that is re- 
moved, the tendency is to seek new affinities and form 
new compounds. On the other hand, inorganic are gen- 
erally burnt bodies. Their chemical affinities are satis- 
fied, and hence at rest. 

The Member of Carbo?i Compounds greatly 
exceeds that of all the other elements combined, and is 
constantly increasing. The labor of modern chemists is 
largely devoted to the subject, and the field opens and 
broadens with every discovery. The methods of classifi- 
cation are unsettled,* and new and conflicting theories 
yet contend on this border-ground of chemical knowl- 
edge. 

Isomerism . — Isomeric compounds are those which 
consist of the same elements in the same proportion. 
— Example : Sugar and gum-arabic have the same 
molecular formula, C| 2 H 2 20,,. — Gelis. The difference 
between such compounds has been supposed to lie in a 
dissimilar grouping of the atoms about one another, as the 
same pieces upon a checker-board may be variously ar- 
ranged ; or as the letters p-l-e-a may also spell 1-e-a-p, or 
p-e-a-1, or p-a-l-e : yet nothing is definitely known. 

Allotropism . — The individual elements are also sus- 
ceptible of allotropic states ; as, for instance, the C in a 
compound may be in any one of its three allotropic forms. 
These two principles of isomerism and allotropism run 
through organic chemistry, and account, in some measure, 
for the immense number of its compounds. Still, one 

* Even Miller, in his great work on the Elements of Chemistry, which em- 
bodies the best results of modern research, uses the same division as the older 
authorities, and nearly the same as that which was adopted in the former edition 
of this work. 



181+ 



OR G A NIC CHEMISTR T. 



can hardly understand how defiant gas and india-rubber, 
the fragrance of a rose and the odor of a kerosene-lamp, 
should consist of the same elements, C and H, only in 
varying proportions. 



STARCH, WOODY FIBRE, AND SUGAR. 



Fvj. 68. 




Potato Starch. 

cent.; 3, in the base of 
their leaves, as the on- 
ion ; 4, in the seed, as 
corn, of which it forms 
about 80 per cent.; 5, 
in the embryo, as the 
bean, the pea, etc. In 
all these it is stored up 
for the future growth of 
the plant. It is kept in 
its starch form (lest it 



1 . STARCH. 
(C 6 H 10 5 .) 

Source. — Plants ac- 
cumulate it, 1, in their 
roots, as the carrot, the 
turnip, etc. ; 2, in sub- 
terranean stems, as 
the potato, of which it 
forms about 20 per 

Flj 69. 




Wheat Starch. 



ST A R C H. 185 

dissolve in the first rain), and then turned to sugar 
only when the plant needs it in growing. (See p. 194.) 
Under the microscope, each vegetable is found to have its 
peculiar form of starch granule, so that in this way any 
adulteration is easily detected.* 

Preparation. — Starch is made from wheat, corn, pota- 
toes, etc. The process is essentially the same in all. The 
potato, for example, is ground to a pulp, and then w T ashed 
with cold water. The starch settles from this milky mass 
as a fine, white precipitate. 

Properties. — Starch is insoluble in cold water; in hot, 
it absorbs H 2 0, swells, and the 
granules burst, forming a jelly- 
like liquid, used for starching. 
The swelling of rice, beans, etc., 
when cooked, is owing to this 
property. By heating to 400° 
when dry, starch undergoes a 

peculiar Change into a Substance Bursting of Starch Granule. 

known as dextrine, f used as a 

mucilage on envelopes and adhesive stamps, for making 
" fig-paste," and stiffening chintzes. The test of starch is 
I, which forms in solution the blue iodide of starch. Sago 
is the starch from the pith of the palm-tree ; tapioca and 



* " The structure of the grains of starch is very beautifully displayed by placing 
some of them in contact with a drop of concentrated solution of zinc chloride 
(tinged with a little free iodine) on the field of the microscope. No change takes 
place in the granules until a little water is added. They then become of a deep 
blue color, and gradually expand ; at first a frill-like plaited margin is developed 
around the globule ; by degrees this opens out ; the plaits upon the globule may 
then be seen slowly unfolding, and may be traced in many cases into the wrin- 
kles of the frill ; ultimately the granules swell up to twenty or thirty times their 
original bulk, and present the appearance of a flaccid sac." — Busk. 

t Dextrine is isomeric with starch, but is not discolored by I. 




186 ORGANIC CHEMISTRY. 

arrow-root are made from the roots of South American 
marshy plants.* 

Gum is found in the juices of nearly all plants, and 
frequently exudes, as in the peach, plum, and cherry. It 
is soluble in water, but not in alcohol. Gum-arabic, which 
flows in transparent tears from an acacia tree, is the 
purest form.f Mucilage, which occurs in gum tragacanth, 
linseed, quince-seed, etc., is a modification of gum, and is 
insoluble in H 2 0. It forms with it, however, a gelatinous 
liquid, which is exceedingly useful. 

Vegetable Jelly. — A variety of gum called pectose 
exists in nearly all fruits and vegetables. It gives to 
them their hardness while green. — Fremy. In the pro- 
cess of ripening, or by heat, acids, etc., it is turned into 
pectin. We find this abundant in the thick juice which 
exudes from an apple while baking. In the making of 
jellies, pectose is converted into a mixture of pectosic 
and pectic acids. 



2. WOODY FIBRE (C 5 H 10 O 5 ). 

Sources. — If a thin slice of wood be examined under 
the microscope, it will be seen to consist of a fibrous sub- 
stance incrusted and compacted with woody matter. The 
former is called cellulin (C 6 H l0 5 ).t It composes the cells 



* Very many of the farinaceous preparations sold for the sick and invalid, 
under high-sounding names, are simply wheat or corn starch. 

f It is a soluble salt, being composed of arabic acid (C 12 H 22 O n , Gelis), com- 
bined with K and Ca. 

X It is probable that the molecule of woody fibre is some multiple of this for- 
mula, as C 18 H 30 15 . 



WOODY FIBRE. 187 

of all plants, giving them strength and firmness, and is 
found even in delicate fruits, holding their luscious juices. 
It occurs in various modifications, in wood, nut-shells, and 
fruit-stones. In the heart of a tree, its cells are hard and 
dense ; in the outer part, they are soft and porous ; in 
elder-pith and cork, light and spongy ; in flax and cotton, 
long, pliable, and fibrous ; in the bran of wheat and corn, 
digestible. 

Sec7*etio?i . — All vegetation consists of these simple 
cells. They seem alike to the eye, yet they have a very 
diverse power of secretion. The cell of the sugar-maple 
converts its sap into sugar ; the milk-weed, into a milky 
juice; the caoutchouc, into rubber; the rhubarb-plant, 
into oxalic acid ; and the rose-petal, into the most delicate 
of perfumes. 

Cells are always true to themselves. There seems to be 
a law of God stamped on each one, so that when we cut a 
tiny bud from one tree and graft it into another, it remains 
consistent with itself. It develops into a limb, and years 
pass by. The few single cells become a myriad, yet they 
have not changed. The sap flows upward in the tree ; 
but at a certain point — a hidden threshold which no 
human eye can discern, it comes under a new and strange 
influence. Here it is transformed, and produces fruit 
and flowers, in accordance with another and different 
growth. Somehow quince- juice is made into pears, 
locust-juice blooms out into fragrant acacias, and sweet 
and sour apples hang upon the same limb. 

Uses. — These are wonderfully various. Woody fibre is 
woven into cloth, built into houses, twisted into rope, 
twine, and thread, pressed into paper, cut into fuel, 
carved into furniture. We eat it, wear it, walk on it, 



188 ORGANIC CHEMISTRY. 

write on it, sit on it, print on it, pack our clothes in it, 
sleep in it, ride in it, and burn it. 

Paper is made from cotton, linen, straw, or any sub- 
stance containing cellular tissue. The finest writing- 
paper is manufactured from linen rags. These are first 
" shredded " upon scythe-blades — L e., the seams are ripped 
open, buttons cut off, and the dust shaken out. 2d. 
They are steamed in a solution of chloride of lime for ten 
or twelve hours until they are thoroughly bleached. 3d. 
They are received by a machine that alternately lacerates 
them by a cylinder set with razor-like blades^ and washes 
them with pure, cold water for six hours, until they 
are reduced to a mass resembling rice and milk. 4th. 
This pulp receives a delicate blue tint from smalt.* 5th. 
It is diluted with H 2 nearly to the consistency of milk, 
and strained to remove the waxed ends and knots of 
thread that cause the little lumps which catch our pen 
when we write rapidly on poor paper. 6th. It flows over 
an endless belt of wire-gauze, about thirty feet in length, 
through which the water steadily drips from the pulp, as 
it slowly passes along, gaining consistency and firmness. 
7th. It comes to a part of the belt called the " dandy- 
roll," consisting of a cylinder, on the surface of which are 
wires arranged in parallel rows, or fancy letters, which 
print upon the moist paper a design — constituting what 
is termed "laid," or "wire-woven," paper. 8th. The 
paper, very soft and moist as yet, passes between rollers 
that squeeze out the water ; then between others which 
are hot, and dry it. 9th. It comes to a vat of sizing, com- 
posed of glue and alum, into which it plunges, and at the 

* Powdered glass colored with oxide of cobalt. 



WOODY FIBRE. 189 

opposite side emerges only to go between other rollers that 
press and dry it — at the end of which it passes under a 
cylinder, set with knives that clip the roll into sheets of 
any desired size. 

Paper 'Parchment is prepared by plunging unsized 
paper for a few seconds in H 2 S0 4 of a specified strength, 
then washing off the acid. This, in some unknown way, 
changes its appearance and character, so that it resembles 
parchment, while its toughness is five times that of the 
paper from which it was made. 

Ijinen is made from the inner bark of flax. The 
plant is first pulled from the ground to preserve the en- 
tire length of the stalk ; next " rotted " by exposure to 
air and moisture, when the decayed outer bark is removed 
by "breaking;" then, by " hatcheling," the long, fine 
fibres are divided into shreds, and laid parallel, while the 
tangled ones are separated as " tow." It is then bleached 
on the grass, which renders the gray coloring-matter sol- 
uble by boiling in lye. The whitened flax is lastly woven 
into cloth. 

Cotton consists of the beautiful hollow, white hairs 
arranged around the seed of the cotton-plant. As it is 
always pure and white — except Nankin cotton, which is 
yellow — it would require no bleaching did it not become 
soiled in the process of spinning, etc. 

Pyroxylin {pur, fire, and xulon, wood), Gun- Cotton, 
is prepared by dipping cellular tissue — cotton, saw-dust, 
printing-paper, etc. — in a mixture of H N0 3 and H 2 S0 4 of 
a certain specific gravity. It is then carefully washed 
and dried. It is not materially changed in appearance, 
but a part of its H has been replaced by N0 2 , and it has 
become very inflammable. It will burn at a temperature 



190 ORGANIC CHEMISTRY. 

more than 200° below that required to ignite gunpowder, 
while its explosive force is much greater. 

Collodion is a solution of gun-cotton in sulphuric 
ether and alcohol. It forms a syrupy liquid, which is 
much used by photographers. 

3 . SUGAR. 

CANE-SUGAR (C, 2 H 22 0,,),* Sucrose, is obtained from 
the sap of the sugar-maple, and the juice of the sugar-cane, 
sorghum, and beet. In making it from the sugar-cane, 
the canes are crushed between iron cylinders, to express 
the juice. As the liquid sours very soon, from the heat 
of the climate in which it grows, a little lime is added to 
neutralize the acid, and it is then evaporated to a thick 
jelly, and set aside to cool. The sugar crystallizes read- 
ily, forming brown sugar, which is put in perforated casks 
to drain. The drainings, "mother-liquor," constitute 
molasses. 

3Zefi?ii7ig . — Brown sugar is dissolved in H 2 0, filtered 
through twilled cotton to remove the coarse impurities, 
and then through a deep layer of animal charcoal. The 
colorless solution is next evaporated in vacuum pans from 
which the air is exhausted, so that the sugar boils at so 
low a temperature as to avoid all danger of burning. 
When sufficiently concentrated, the liquid is removed and 
set aside to crystallize. If the mass of crystals is dried in 
moulds, it forms loaf sugar; if in centrifugal machines, 



* A very brilliant experiment showing the presence of C in C ls H, 2 O u is 
obtained by putting on a clean, white plate, a mixture of finely-pulverized white 
sugar and KC10 3 . Upon adding a few drops of H 2 S0 4 , a vivid combustion w T ill 
ensue. By mixing with the sugar a few iron and steel filings, and performing 
the experiment in a dark room, or out of doors at night, fiery rosettes will flash 
through a rose-colored flame, and produce a fine effect. 



WOODY FIB BE. 191 

granulated sugar? The drainings constitute "syrup," 
" sugar-house molasses," etc. 

Co?ifeclio?iery '. — Terra alba (white earth), is im- 
ported from Ireland for use in lozenges, drops, etc.f 
Confectionery is often colored "by dangerous poisons, so 
that prudence would forbid the use of any colored candy. 
Licorice drops are frequently only the poorest brown 
sugar, terra alba, and a flavoring of licorice to make the 
unwholesome mixture palatable. Gum-drops are made, 
not from gum-arabic, but generally of a species of glue 
manufactured out of hoofs, parings of hides, etc. How- 
ever repugnant it may appear, this substance is perfectly 
clean and wholesome. Eoek candy is formed by suspend- 
ing threads in a strong solution of sugar. It crystallizes 
upon the rough surface in large, six-sided prisms. 

Caramel, familiarly called burnt sugar, is formed 
whenever sugar is heated to about 420°, as when sweet- 
meats boil over on the stove; H 2 is lost and C remains 
in excess. It is used by confectioners and for coloring 
liquors. 

GRAPE-SUGAR (C 6 H l2 6 ), Dextrose, is found in honey, 
figs, and many kinds of fruit. Its sweetening power is 
about two-fifths that of cane-sugar. 

Sugar from Starch. — The difference in the con- 
stitution of starch and grape-sugar is only H 2 0. By 

* This apparatus consists of a cylindrical drum mounted upon a vertical axis, 
to which a rapid rotary movement can be given. The outer side of this drum is 
made of a stout but closely-woven network. The drum is inclosed in a large, 
fixed, cylindrical vessel capable of holding the liquid which may pass out through 
the network. A charge of syrup is placed in the inner drum, which is then made 
to revolve rapidly. The syrup escapes through the wire-gauze into the outer 
drum while the crystals are rapidly dried. 

t We can and should test all the candy we purchase by putting a small piece in 
a glass of water. Whatever settles to the bottom and remains undissolved is an 
adulteration. 



192 ORGANIC CHEMISTRY. 

slowly heating potato-starch with dilute H 2 S0 4 it is 
transformed into a syrup, from which the. dextrose will 
separate in crystals. The weight of the sugar will exceed 
that of the starch by the additional H 2 0. The acid acts 
by catalysis, being itself unchanged in the process.* 

€ ' Ca?z died Jetties, 'Preserves, etc . y \ — The 
sugar of many kinds of ripe fruits consists of grape or 
cane sugar mixed with fruit sugar. The latter changes 
gradually into grape sugar, and crystallizes as in honey, 
dried figs, etc.f 



FERMENTATION. 

If a solution of starch or grape-sugar be exposed to the 
air it will undergo no change ; but if there be 'added a 
little ferment, J or any albuminous substance (i. e., one 

* Saw-dust, paper, and even rags can in the same way be converted into sugar. 
Indeed, Prof. Pepper speaks of seeing some made out of an old shirt. Wonderful 
beyond our comprehension is that chemical force which can transform a cast-off 
garment into a substance which will delight the palate, or a snowy page on which 
thought may be inscribed. Thus the chemist faintly imitates nature, which, 
ever out of waste and refuse, springs afresh. The fair petals of the lily rest upon 
the black mud of the swamp, and the products of decay come back to us in 
objects of use and forms of beauty. 

t Grape sugar is isomeric with fruit sugar, but is much sweeter. The former, 
as it is noted for its right-handed rotation of the plane of polarized light, is called 
dextrose (dextra, right), and the latter, from its left-handed rotation, laevulose 
(Icevus, left). (See Physics, p. 170.) 

$ In many cases, spontaneous fermentation sets in without the apparent 
addition of any ferment: thus wine, beer, milk, etc., when allowed simply to 
stand exposed to the air, become sour, or otherwise decompose. These changes 
are, however, not effected without the presence of vegetable or animal life, and 
are true fermentations . the sporules, or seeds of these living bodies, always float 
about in the air, and on dropping into the liquid begin to propagate themselves, 
and in the act of growing evolve the products of the fermentation. If the above 
liquids be left only in contact with air which has been passed through a red-hot 
platinum tube, and thus the living sporules destroyed; or if the air be simply 
filtered bypassing through cotton wool, and the sporules prevented from coming 
into the liquid, it is found that these fermentable liquids may be preserved for 
any length of time without undergoing the slightest change.— Roscoe. 



FERMENTA TI N. 193 

containing N), in a decomposing state, it will immedi- 
ately commence breaking up into new compounds. The 
ferment acts by catalysis, its presence seeming to over- 
come the unstable equilibrium of the chemical forces, 
and causing the large molecules to drop into smaller 
ones. There are two stages in this chemical change. 

1st. Alcoholic JFermenlatwi . — In this, the grape- 
sugar is resolved into alcohol and carbonic anhydride. 
The former remains in the liquid, while the latter 
escapes in little bubbles of gas. The reaction may be 
represented thus: C 6 H, 2 6 :=2C 2 H 6 + 2C0 2 . 

2d. Acetic Fermentation . * — The second stage 
succeeds the first immediately, if not checked, and by ab- 
sorbing from the air, the alcohol is broken up into 
acetic acid and water ; thus, C 2 H 6 +0 2 (from the air) = 
C 2 H 4 2 + H 2 0. 

Yeast is formed during the process of fermentation. 
It consists of microscopic plants {Mycoderma cerevisice) 
which increase by the formation of multitudes of tiny 
cells not more than y Iq of an inch in diameter. In the 
brewing of beer they spring up in great abundance, mak- . 
ing common brewer's yeast. f 

Mall. — In making malt, the barley is thoroughly 
soaked in water, and then spread on the floor of a dark 
room, to heat and sprout. Here a curious change ensues, 
identical with that which takes place in every planted 
seed. Each one contains starch and a nitrogenous sub- 



* There are also other forms of fermentation, as the lactic, yielding lactic acid— 
the acid of sour milk ; butyric, yielding butyric acid, etc. 

t The yeast-cakes of the kitchen are formed by exposing moistened Indian 
meal, containing a ferment, to a moderate temperature, until the gluten or albu- 
minous matter of the cake has undergone this alcoholic fermentation. They are 
then laid aside for use. 

9 



194 ORGANIC CHEMISTRY. 

stance called gluten. The tiny plant not being able to 
support itself in the beginning, has here a little patri- 
mony with which to start in life ; but, as the starch is 
insoluble in the sap, it must first be changed to a soluble 
form. We see, therefore, the need of a ferment ; but it 
would not answer to store up in the seed an active fer- 
ment, as that might cause a change before the plant was 
ready to grow, and thus the plant's capital be wasted. 
The gluten acts, therefore, as a latent ferment. As soon 
as the seed is planted it absorbs moisture from the ground, 
is turned into diastase — an active ferment * — the starch 
is converted into dextrine and sugar, dissolved, and imme- 
diately applied to the uses of the growing plant. This 
change takes place in the malting-room. The barley 
sprouts, and a part of its starch is turned to sugar, so as 
to give it a sweetish taste. If this germination were 
allowed to proceed, the little barley sprout would turn 
the sugar into woody fibre. To prevent this, the grain is 
heated in a kiln until the germ is destroyed. Barley in 
this condition is called malt, and is then transported to 
the breweries. 

^Brewing Seer. — The malt is crushed and digested 
in water, to convert the remaining starch into dextrine 
and sugar. Hops and yeast are added, and fermentation 
immediately commences. Bubbles of gas rise to the top 
with a low hissing sound, yeast gathers in a foamy cream 
that comes to the surface of the tub, while the alcohol 
gradually accumulates in the liquid. The beer is now 
drawn off into tight casks, where it undergoes a second 



* Malt does not contain more than 5^ of its weight of diastase ; one part of 
this substance being sufficient to change 2,000 parts of starch into dextrine and 
sugar.— Pbrsoz and Paten. 



FERMENTA TIO N. 195 

fermentation; the flavor ripens, and the C0 2 collecting, 
gives to the liquor, when drawn, its sparkling, foamy 
appearance. 

Imager "Seer {Lagern, to lie) is so called because it 
is allowed to lie for months in a cool cellar, where it 
ripens very gradually. It is also fermented much more 
slowly and perfectly than ale or porter. 

Wine is made from the juice of the grape. The juice, 
or must, as it is called, is placed in vats in the cellar, 
where the low temperature produces a slow fermentation. 
When all the sugar is converted into alcohol and C0 2? a 
dry wine remains ; when the fermentation is checked, a 
sweet wine is the result; and when bottled while the 
change is still going on, a brisk, effervescing wine, like 
champagne, is formed. The flavor or " bouquet " of wine 
is due to the slow formation of a fragrant and aromatic 
ether.* (See p. 204.) The tartaric acid of the grape 
gradually separates and collects on the sides and bottoms 
of the casks in a white incrustation — cream of tartar. 

AlcoJiot in Seer, Wine, etc. — Alcohol is the 
intoxicating principle of all varieties of liquors, ale, beer, 
wine, cider, and the domestic wines. Ale and porter 
contain from 6 to 8 per cent, of alcohol ; wine varies from 
7 per cent, in the light claret to 17 per cent, in the strong 
Port and Madeira ; brandy and whisky have from 40 to 
50 per cent. 

Ardent Spirits. — When any fermented liquor is 
distilled, the alcohol passes over, together with water 
and some fragrant substances which are condensed. In 
this way brandy is made from wine ; rum from fermented 

* (Enanthic ether, a liquid with a powerful odor, which causes the peculiar 
smell of grape-wine. 



196 



ORGANIC CHEMISTR T. 



molasses or cane-juice; whiskey from fermented corn, 
rye, or potatoes ; and gin from fermented barley and rye, 
afterward redistilled with juniper-berries. The accompa- 
nying cut represents an apparatus used for this distilla- 



Mg. 71. 




A Still. 

tion. A is the boiler, B the dome, C a tube passing into 
S, the condenser, where it is twisted into a spiral form 
called the worm, in which the vapor from the boiler is 
condensed, and drops out at D. (See Physics, page 
188.) 

Alcofiol (C 2 H 6 0)* is prepared by distilling whiskey, 
and is sometimes called spirits of wine. It boils at 173°, 
and has never been frozen even at —166° F. It contains, 



* Ethyl alcohol or vinic alcohol. It is also known as ethyl hydrate. (See 
Marsh-gas Series, p. 201.) 



FE R M E NT A TI ON. 197 

when strongest, 10 per cent, of H 2 0, which can be sepa- 
rated by adding some substance like lime, which has a 
strong affinity for H 2 0. It is then called anhydrous or 
absolute alcohol. When C 2 H 6 is exposed to the air the 
spirit evaporates, while moisture is absorbed from the 
atmosphere.* It burns without smoke and with intense 
heat, owing to the abundance of H and deficiency of C, 
and is therefore of great value in the arts. It is also of 
incalculable importance as a solvent of many substances 
— roots, resins, fragrant oils, etc. 

JUffects of Alcoliol. — When pure it is a deadly poi- 
son. W^hen diluted, as in the ordinary liquors, it is stim- 
ulative and intoxicating. Its influence is on the brain 
and nervous system ; — deadening the natural affections, 
dulling the intellectual operations and moral instincts ; 
seeming to pervert and destroy all that is pure and ho]y 
in man, while it robs him of his highest attribute — 
reason. (See Physiology, p. 150.) 

JzJther [(C 2 H 5 ) 2 0]. — Sulphuric Ether is formed by the 
distillation of C 2 H 6 with HgSO^.f It has a fragrant 
odor, boils at about 94°, and burns with more light and 
smoke, but less heat, than alcohol. Its vapor is thirty- 
seven times heavier than H, and can be poured like C0 2 .J 
By the action of different acids on C 2 H 6 0, other ethers 
are produced, viz., nitric, acetic, butyric, § etc. 

* The chemist discovers this when he neglects to put the extinguisher on his 
alcohol-lamp, and finds that he cannot relight it without moistening the wick 
with fresh alcohol. 

t Though thus named, this ether contains no S. It is known as ethyl oxide. 
(See page 202.) 

X It should be used with care in the presence of a light, as it is inflammable and 
becomes explosive when mixed in proper proportions with air. 

§ This has the odor of pine-apple, and is sold as pine-apple oil. The melon 
and straw T berry are supposed to owe a portion of their flavor to this ether. 



198 ORGANIC CHEMISTRY. 

Chloroform (CHC1 3 ) is made by distilling C 2 H 6 
with chloride of lime. It is colorless,, volatile, of a sweet 
taste, and should be free from any unpleasant odor 
when evaporated on the hand. It is used as a solvent of 
I, P, S, and caoutchouc, and as an anaesthetic. The value 
of ether and chloroform in alleviating pain, is beyond 
estimate. 

Chloral (C 2 Cl 3 HO) is formed by passing CI through 
absolute alcohol. It is an oily liquid which combines 
with H 2 0, making Chloral Hydrate, a white, crystalline 
substance, much used to induce sleep. Taken in proper 
quantities it is entirely safe, and is exceedingly pleasant 
in its influence. 

Acetic A.cid (C 2 H 4 2 , acetum, vinegar) forms from 
two to four per cent, of common vinegar, whence its 
name. The strongest acetic acid is known as the glacial, 
since it crystallizes into an ice-like solid at 63°. It has 
an aromatic taste and pungent odor, and, after a time, 
blisters the skin. 

Fig 72 Preparation. — Vinegar is made on a 

large scale by filtering a mixture of alco- 
hol and yeast through a cask filled with 
beech shavings soaked in vinegar. As the 
fermenting alcohol slowly trickles down, 
it comes in close contact with the air, 
absorbing so rapidly that sometimes 
before it reaches the bottom it becomes 
Making vinegar. erL tirely converted into vinegar. 

Cider Yinegar. — Cider contains some nitrogenous 
matter, which acts as a ferment, by which the starch of 
the apple is broken up into C 2 H 6 and C0 2 . This 
makes what is called " old cider P By exposure to the air 




FEFMENTA TIO N. 199 

and heat, the alcohol passes on to the second stage, and 
the acetic acid formed produces the sour taste of the vin- 
egar.* 

Properties. — Acetic acid is a solvent of albumen, gela- 
tin, fibrin, etc. Hence it takes from meat, eggs, oysters, 
etc., their most strengthening constituents. For a simi- 
lar reason, vinegar is a valuable assistant in digesting 
such food. It allays thirst, and was anciently carried by 
the Roman soldiers in a little flask for that purpose. 
Sugar added to vinegar quickly passes to the second stage 
of fermentation, and increases its strength. Indeed, 
vinegar is sometimes made entirely from sweetened water 
and tea-leaves, which act as a ferment. Vinegars of 
commerce are often sharpened by the addition of H 2 S0 4 
and pungent spices, f 

'Preserves frequently " work," as it is called, and then 
sonr. The bubbles of gas which rise to the surface indi- 
cate the alcoholic fermentation. If neglected, this soon 
passes to the acetic stage. It may be checked by scald- 
ing, which destroys the ferment. 

Aldehyde. — A molecule of alcohol absorbs two atoms 
of from the air, as we have seen, forming acetic acid 
and water. In this process, there is an intermediate step 
during which the two atoms of H combine with one atom 
of 0, forming a molecule of water. This intermediate 



* Mother, in vinegar, is a fungus (Mycoderma aceti) produced by the decom- 
position of the nitrogenous matter. It absorbs O from the air and gives it up to 
the alcohol. 

+ We can easily detect these by evaporating a half-gill in a saucer, placed over 
hot water. As it boils down, add a little sugar, taking care not to allow it to 
burn. If the liquid turns black, it is proof of the presence of H 2 S0 4 . As the 
last evaporates, the odor of cayenne pepper, etc. (if there be any), can be readily 
distinguished.— In England, commercial vinegar is permitted by law to have one 
part in a thousand of oil of vitriol, as this keeps it from moulding. 



200 ORGANIC C HE MI S TRY. 

substance is called aldehyde,* which quickly absorbs a 
second atom of 0, producing acetic acid. 



ORGANIC RADICALS. 

A eadical is the root of a series of compounds 
which differ from each other by a constant amount. 
Such series are said to be homologous (homos, same; 
logos, proportion), and the different members to be homo- 
logues of each other. 

flfarsJi-gas Series. — Marsh-gas, CH 4 (page 81), is 
the first member of a series of hydrocarbons, whose com- 
mon difference is CH 2 . The symbol CH 4 maybe written 
(CH 3 )H, and considered as the hydride of a group of 
atoms called methyl: hence marsh-gas is called methyl 
hydride. Methyl is the radical of a series of compounds, 
and plays the part of an element in various chemical 
reactions. The other members of the series may be writ 
ten in the same way, and arc regarded as hydrides of 
the radicals ethyl, propyl, butyl, etc. 

Methyl Hydride (Marsh-gas) CH 4 =CH 3 ,H 

Deutyl or Ethyl Hydride C. 2 H 6 = C 2 H 5 ,H 

Trityl or Propyl Hydride C 3 H 8 =C 3 H 7 ,H 

Tetryi or Butyl Hydride C 4 H , = C . H 9 ,H 

Pentyl or Arnyl Hydride C 5 H , 2 =C 5 H , , ,H 

Hexyl Hydride. . .♦. C 6 H , 4 = C 6 H , 3 ,H 

Heptyl Hydride. . C 7 H , 6 = C 7 H , 5 ,H 

Octyl Hydride C 8 H 18 =C 8 H , 7 ,H 

Nonyl Hydride C 9 H 20 = CgH 19 ,H 

etc. etc. 

* The odor of aldehyde may be obtained by holding a red-hot coil of Pt wire 
in a goblet containing a few drops of alcohol. This experiment, showing the 



ORGANIC R A DIC A L 8. 201 

The Alcofiols. — Common alcohol, C 2 H 6 0, may be 
written C 2 H 5 ,HO, which is. the hydrate of the radical 
ethyl ; hence it is known as the ethyl hydrate. Each of 
the other radicals just named has its hydrate or alcohol. 
In some cases it has not yet been separated, though its 
symbol is known, and the body is believed to exist. The 
series has been continued as high as melyl alcohol, 

Boilin? 
Point. 

Methyl Alcohol (wood-spirit) *. . . . CH 4 = C H 8 ,H 66° C 

Ethyl Alcohol C 2 H 6 = C 2 H,„HO .... 78° 

Propyl Alcohol C ; H s O =C ;{ H 7 ,HO .... 96° 

Butyl Alcohol C 4 H, u ==C 4 H 9 ,HO ....109° 

Amyl Alcohol (fusel oil) f C 5 H 12 =C 5 H M ,HO ....132° 

Hexyl Alcohol C : H l4 = C 6 H 13 ,HO ....150° 

Heptyl Alcohol C 7 H, 6 6 = C 7 H 15 ,HO ....164 

C s H !8 =C 8 H 17 ,HO .... 

C 9 H 20 =C 9 H 19 ,HO .... 

Decatyl Alcohol . X 10 H 22 O^C ]0 H 21 ,HO. . . .212° 

MdeJiydes a?id Acids. —Ethyl, or common alco- 
hol, by an oxidizing agent loses two atoms of H, and is 
changed, as we have seen, to C 2 H 4 0, or ethyl aldehyde. 
This can be further oxidized into acetic acid. Each of 



formation of aldehyde from alcohol, may be very profitably followed by another, 
illustrating the change of alcohol into acetic acid. Place a little platinum black 
in a watch crystal, near a small cup of alcohol. Cover them both with a glass 
receiver, and set them in the sunlight. Soon a mist will gather, and tiny streams 
of the condensed vapor of acetic acid will collect and run down the sides of the 
glass. Fresh air must be occasionally admitted to oxidize the alcohol. 

* Methyl alcohol is very like ethyl alcohol, and is used for similar purposes, as 
dissolving resins, etc. Methylated spirit is ethyl alcohol with about 10 per cent, 
of wood spirit, which does not injure it for many uses to which ordinary alcohol 
is applied. 

+ This is formed in distilling whiskey from potatoes. It is present in common 
C a H e O, giving a slightly unpleasant odor when it evaporates from the hand. 
It is extremely poisonous, and as it is often contained in liquors, must greatly 
increase their destructive and intoxicating properties. 



202 ORGANIC CHEMISTRY. 

the alcohols can thus be oxidized, and will yield an alde- 
hyde and an acid. The following is a list which is more 
complete even than that of the alcohols themselves : 

Source. 

Formic Acid* CH 2 2 Red ants, oxalic acid, etc. 

Acetic Acid. C. 2 H 4 2 Alcohol, distillation of 

Propionic Acid ...C ; ^H 6 2 Glycerin. [wood. 

Butyric Acid C 4 H 8 2 Butter. 

Valerianic Acid C 5 H , 2 Valerian root. 

Caproic Acid C 6 H , 2 2 Butter. 

(Enanthyiic Acid C 7 H 14 2 Castor oil. 

Capric Acid .C 8 H , 6 0. 2 . . „ . . .Butter. 

Pelargonic Acid C 9 H ]8 2 Geranium leaves. 

Rutic Acid C , () H 2() 2 Oil of rue, butter. 

Laurie Acid C , 2 H 2 4 2 Berries of bay tree. 

Myristic Acid C , 4 H ., 8 ., Nutmeg butter. 

Palmitic Acid f C 16 H,,0 2 Palm oil. 

Margaric Acid f C , 7 H 3 4 O 2 Animal fats. 

Stearic Acid j. ....C l8 H 36 2 " 

Arachic Acid C , n H 4 O 2 Butter, 

Bebenic Acid C 22 H 44 2 

Hyaenic Acid C 2 5 H 50 O 2 ..... . 

Cerotic Acid C 3 7 H 54 2 Beeswax. 

Melissic Acid C 30 H 6 JOt " 

2*he JPthers. — Common ether is formed, as we have 
seen, from ethyl alcohol by the action of H 2 S0 4 ; and its 
symbol, (C 2 H 5 ) 2 0, represents that it is considered as 
ethyl oxide. Each of the other alcohols J has its ether — 
the oxide of its radical. Thus, 

* Formic acid, which was found in red ants (Formica rufa), is a fiery, pungent 
fluid, which blisters the skin. It is made from methyl alcohol, as acetic acid 
is from common or ethyl alcohol. 

t Palmitic, margaric, and stearic acids, are known as the fatty acids (see 
page 218), and are of great value in the arts. 

t The term alcohol is now applied to those neutral compounds of H, C, and O, 
which react upon the acids, eliminating water and forming ethers. 



ORGANIC RADICALS. W8 

Methyl Ether C 2 H 6 =(CH 3 ) 3 

Ethyl Ether C 4 H 10 =(C 2 H 6 ) 8 

Propyl Ether C 6 H , 4 =(C 3 H 7 ) 2 

Butyl Ether C 8 H 1 8 =(C 4 H 9 ) 2 

Amyl Ether C, H 22 Orr(C 5 H 11 )2O 

Compound Ammo?iias. — Each alcohol also forms 
a series of compound ammonias. H 3 N may be written 

H } 

thus, h (. n, and one or more atoms of H may be replaced 
by a radical. In the ethyl series, for example, we have 

C a H 5 ) C a H 5 ) C 2 H 5 ) 

h v n, or ethylamine; c 2 h 5 I n, diethylamine ; c 2 h 5 I n, 

H ) H ) C2H5 ) 

triethylamine. These ammonias closely resemble com- 
mon ammonia, neutralize acids, produce white clouds with 
H CI, and form crystallizable salts; though they steadily 
rise in their boiling point. 

Salts of the ^Radicals '. — The symbol for water 

may be written thus, H J- ; caustic potash, Ho; and 

ethyl alcohol after the same type, CaH5 t o. As by adding 

HC1 to KHO we obtain KG and H 2 0, so we can form the 
chlorides, iodides, bromides, etc., of all the radicals of the 
marsh-gas series by treating the alcohol with the proper 
acid. Ethyl, for example, thus furnishes compounds 
analogous to the potassium salts. 

K ) 
1. Potassium nitrate v.q y O. 

1. Ethyl nitrate (Ethyl-nitric ether) j^ 5 I 0. 

K ) 

2. Hydrogen-potassium-sulphate H f S0 4 . 

2. Hydrogen- ethyl-sulphate (Sulphuric ether*). Cz ^ 5 [ S0 4 . 
* This, rather than ethyl oxide (see p. 197), is the true sulphuric ether; com- 



20 Jf. ORGANIC CHEMISTRY 

K ) 
3. Potassium sulphate ^ [■ S0 4 . 

3. Ethyl sulphate (Ethyl-sulphuric ether) c*H - [ S ° 4 ' 

4. Potassium acetate 2 „ * t 0. 

4. Ethyl acetate (Ethyl-acetic ether) £ 2 JJ 3 ° I 0. 

The salts of the radicals are often termed compound 
ethers, to distinguish them from the simple ethers, which 
are the oxides. They are extensively sold as flavoring 
extracts for the use of confectioners and cooks. The 
essence of jargonelle pear is an alcoholic solution of amyl 
acetate ; apple oil, of amyl valerianate ; pine apple, of 
ethyl butyrate. 



There are many series of organic bodies, of which those 
given are merely illustrations. The various changes 
which they can undergo indicate what a wide field lies 
open for discovery, and the multitude of possible organic 
compounds. 



DESTRUCTIVE DISTILLATION. 

1. DECAY. — When wood decays slowly in the open 
air, the H passes off, the proportion of C increases, the 
color darkens, and a black carbonaceous mass remains, 
called llamas. This is of great value to the soil, as its 
pores absorb H 3 N, which, together with C0 2 produced by 



pare its formula with that of sulphuric acid, showing it to be a true salt as de- 
fined in the note on page 23. 



DESTRUCTIVE DISTILLATION, 205 

its decay, is furnished to the growing plant. When the 
supply of humus is exhausted from the soil, we restore 
it by adding straw, etc., and by plowing in green 
crops. 

2. DISTILLATION.— When hard wood, as beech or 
oak, is heated to a high temperature, with no present, 
or an imperfect supply, it is decomposed ; the charcoal 
remains, while a large number of products are formed, 
among which are H, CO, C0 2? H 2 0, CH 4 , methyl alcohol, 
acetic or pyroligneous acid, creosote, paraffine, tar, etc. 

%*yroligneous Acid (wood-vinegar) is the crude 
acetic acid. It is used in making the acetates from which 
the pure acid is obtained by the action of a stronger acid, 
as H 2 S0 4 . 

Creosote (flesh-preserver) is a colorless, poisonous 
liquid, with a flavor of burnt wood.* It has powerful 
antiseptic properties. It imparts to smoke a character- 
istic odor, renders it irritating to the eyes, and also gives 
to it the power which it possesses of curing hams, 
beef, etc. 

'Paraffine (fiarum, little; affinis, affinity), so called 
because the acids and bases have no effect upon it, is a 
hard, white, tasteless solid, resembling spermaceti. It 
forms beautiful candles, which look and burn like the 
finest of wax. It is a product of the rectification of 
beech -wood tar, but the paraffine of commerce is now 
obtained from petroleum. 

Tar is made, like charcoal, by burning heaps of wood 
under a covering of earth which excludes the air : an 
imperfect combustion ensues, the resinous matter exudes, 

* Much of that which is sold as creosote is carbolic acid. (See page 206.) 



206 ORGANIC CHEMISTRY. 

and, trickling down, runs into a reservoir below. On the 
extensive pine-barrens of North Carolina the tar of com- 
merce is principally produced. 

COAL-TAR is formed in the process of making coal-gas. 
(See p. 81.) It was formerly thought valueless, but is 
now used for a great variety of purposes. On distillation 
it yields, among other products, ammonium salts (see pp. 
83, 135), carbolic acid, benzole, coal-naphtha, and dead-oil. 

Ca?*bolic Acid (Phenic Acid* C 6 H 6 0) is noted for 
its antiseptic and disinfecting properties. By heating it 
with HN0 3 , picric acid is formed. This colors a rich 
yellow, and is a very popular silk dye. The picrates are 
yellow, explosive salts. Potassium picrate is used in 
making certain kinds of gunpowder. 

r S>e?izo2e f is a light oil used as a solvent of gutta- 
percha, caoutchouc, and wax ; for removing grease-spots ; 
as a burning-fluid, etc. Its ready inflammability makes it 
an exceedingly dangerous article. A current of air passed 
through benzole, as well as through any of the other 
light hydrocarbons, will absorb so much vapor that it 
may be burned as an illuminating gas. Machines for 
lighting houses, etc., are based upon this principle. 

A r itro~!$e?izo2e is formed by treating benzole with 
HNO3. I* i s a heavy, oily liquid, with an odor like that 
of bitter almonds. It is chiefly valuable, however, as the 
source of aniline, J from which are prepared the celebrated 

* The formula for carbolic acid is C 6 H 6 0, and maybe written as C 6 H 5 ,H0. 
The acid may then be considered as the hydrate of the radical phenyl, and hence 
is sometimes called phenyl alcohol. Phenyl is the radical of a series of hydro- 
carbons, abundant in the coal-oils. 

t Benzole was so named because of its abundance in benzoic acid. It was for- 
merly sold as benzine, but a cheaper coal-oil has now taken its place. 

% In 1856, Mr. Perkin, while experimenting with aniline in hopes of making 
quinine, treated it with potassium bichromate. He did not succeed in his 



DESTRUCTIVE DISTILLATION. 207 

coal-tar dyes. — Example : mauve, magenta, etc. Who but 
a chemist would have searched in black, sticky coal-tar 
for these rainbow-tints, the stored-up sunshine of the 
carboniferous age ! 

Naphl?ia is a volatile, limpid oil, with a peculiar odor 
and generally a light straw color. It is composed of sev- 
eral hydrocarbons and is very inflammable. Naphthaline 



attempt, but he obtained a beautiful purple dye, which was soon introduced to 
commerce under the name of mawe. A host of imitators at once sought to obtain 
the color without using potassium bichromate. As the only use of the latter was 
to oxidize the aniline, they reasoned that they might use any other oxidizing 
agent. Arsenic, among other substances, was tried, but instead of a purple the 
red known as magenta was the result. The coloring matter, however, does not 
contain any arsenic ; being a salt of a base called rosaniline. Rosaniline itself is 
colorless, and reveals its magnificent tints only in its compounds. '■ The crystals 
of its salts exhibit by reflected light the metallic green color of beetles' wings, 
but are of a deep red color when seen by transmitted light. 1 ' Magenta is manu- 
factured on an enormous scale in England, more as a substance from which to 
obtain other dyes than for direct use in dyeing. A single firm produces twelve 
tons a week. The quantity of magenta furnished by one hundred pounds of coal, 
is very small ; but this is compensated for by its intense coloring power, since it 
will dye a quantity of wool nearly equal in weight to the coal. In making 
magenta on the large scale there are considerable quantities of residual products. 
These of course have been examined with a view to further profit, and the result 
hag been the discovery of a beautiful orange color called phosphine. This is much 
used to produce scarlet, by first dyeing the silk or wool with magenta, and then 
passing it through a bath of phosphine. By treating magenta with aniline, a 
beautiful blue is obtained. This is insoluble in water, but is rendered soluble 
exactly as indigo is, by treating it with sulphuric acid. Another curious dye 
formed from aniline is known as Nicholson's blue. This is completely decolor- 
ized by alkalies, and the color is restored by acids. In dyeing with it, the silk 01 
wool is first immersed in a colorless solution of the dye, and then dipped into 
dilute sulphuric acid, when the blue is at once developed. If magenta is heated 
with iodide of ethyl or methyl, an excess of the iodide being employed, a most 
beautiful green is the result. If, however, this green is heated sufficiently to 
drive off the excess of iodide, a violet color is the result ; so that it will not do for 
ladies wearing dresses dyed with this green to sit too near the fire. After all the 
coloring matter has been extracted from the aniline, a residue remains which 
has an intense black color and is largely used for making printing ink. Very few 
of the aniline colors when in powder give a person any idea of the color which 
they will produce when moistened. Magenta, for instance, when dry, is a beau- 
tiful green with a bronze-like lustre. It is a pretty experiment to coat a sheet of 
glass with one of these colors, which is readily done by dissolving in alcohol 
(Hofmann's violet being the best) and allowing a film of it to evaporate on the 
glass. When seen by transmitted light it is of a beautiful violet, but. with reflect- 
ed light it displays a tint rivalling in brilliancy the tail of a peacock.— Boston 
Journal of Chemistry. 



208 ORGANIC CHEMISTRY. 

is a crystalline solid occurring in beautiful pearly scales. 
It is especially abundant in dead-oil, and may be formed 
by passing olefiant gas or benzole through red-hot tubes. 
Anthracene accompanies naphthaline in the latter part of 
its distillation. It is also a white solid. It is of interest 
since the coloring principle of madder — alizarine— has 
been made from it. 

"Dead- Oil is used for preserving timber ; as a cement 
for roofs and walls ; for oiling machinery, etc. 

PETROLEUM ( jtf^m, a rock ; oleum, oil) is probably 
the product of the distillation of organic matter beneath 
the surface of the earth. It is not always connected 
with coal, as it is often found outside the coal-measures, 
as in New York and Canada. The distillation must 
have taken place at a much greater depth than that at 
which the oil is now found, as it would naturally rise 
through the fissures of the rock and gather in the cavities 
above. Sometimes the oil has collected on the surface of 
subterranean pools of salt-water, so that after a time the 
oil is exhausted, and salt-water only is pumped up ; or if 
the well strikes the lower part of the cavity, the water 
will first be pumped and afterward the oil. The crude 
oil from the well is purified by distillation. That which 
passes over at the lowest temperature is called naph- 
tha : as the heat is increased, there passes off next kero- 
sene oil* for illumination, and lastly lubricating oil. The 



* Kerosene accidents generally rise from the presence of naphtha. This is a 
theap, light, dangerous oil. Its vapor, however, is not explosive unless mixed 
with air. While a lamp, which contains adulterated kerosene, is burning quietly 
there is no danger. The vapor rises from the oil, fills the empty space in the 
lamp, but being unmixed with air cannot explode. Let, however, a draught of 
cold air strike it, or carry it into a cold room — instantly the vapor will be con- 
densed, the air will rush in, and a dangerous mixture be formed. Or when the 
light is extinguished at night the vapor will cool, air pass in, al!d a mixture be 



DESTRUCTIVE DISTILLATION. 209 

kerosene is deodorized and decolorized by the use of 
H 2 S0 4 and other chemicals, which are stirred in the oil, 
after which it is redistilled. 

St turn en or Asphattum. — Petroleum and naph- 
tha, flowing from the ground, have formed beds of bitu- 
men in various parts of the world. This change is caused 
by a gradual oxidation and hardening, as turpentine 
changes to rosin. Tar Lake is situated on the island of 
Trinidad. It is nearly three miles in circumference. 
The bitumen is used for the same purposes as pitch, 
which it closely resembles. Near the shore it is hard 
and compact, except in hot weather, when it becomes 
sticky. At the centre it is soft, and fresh bitumen boils 
up to the surface. Asphaltum is found in immense 
quantities in California and in Canada. It is a natural 
cement for laying stone or brick. It was used in build- 
ing the walls of Babylon, for which purpose it was 
gathered from the fountain of Is on the banks of the 
Euphrates. It was a prominent ingredient in the " Greek 
Fire," so much used by the nations of Eastern Europe in 
their naval wars, even as late as the fourteenth century. 
This consisted of bitumen, sulphur, and pitch, and was 
thrown through long, copper tubes, from hideous figures 
erected on the prow of the vessel. Bitumen is used in 
making the famous promenades of the Boulevards in Paris. 

produced which will be ready to explode when the lamp is relighted. Kerosene of 
the legal standard is no more explosive than water, and will even extinguish a 
flame applied to it at the ordinary temperature. Dr. Nichols gives the following 
simple test : Fill a bowl partly full of hot water. Insert a thermometer, and add 
cold water until the temperature is 110° F. Then pour into the bowl a spoonful of 
kerosene and apply a lighted match. If it takes fire the oil contains naphtha and is 
dangerous ; if not, the kerosene may be used with perfect safety. 



210 ORGANIC CHEMISTRY, 



THE ORGANIC ACIDS. 

There are many vegetable acids found native in plants 
—generally, however, combined with some base. 

Oxalic Acid (C 2 H 2 4 ) is familiar in the sour taste 
of rhubarb, sorrel, etc. In these plants the acid is com- 
bined with K and Ca. It may be prepared by the action 
of HN0 3 on sugar.* It is a potent poison. The antidote 
is powdered magnesia, or chalk, stirred in H 2 0. It is a 
test of lime, forming a delicate white precipitate of cal- 
cium oxalate. A solution of oxalic acid is much used 
to remove ink stains, and is often sold for this purpose 
under the deceptive name of " salts of lemon." The acid 
unites with the Fe of the ink, and the iron oxalate thus 
made is soluble in H 2 0. It should be washed out imme- 
diately, as it will corrode the cloth. 

Tartaric Acid (C 4 H 6 6 ) exists in many fruits, 
principally in the grape, combined with K as hydrogen 
potassium tartrate ("bitartrate of potash"). This settles 
during the fermentation of wine (see p. 195), and when 
purified is called cream of tartar, from which tartaric acid 
is made. It forms transparent crystals of a pleasant acid 
taste, which are permanent in the air. Its aqueous solu- 
tion gradually becomes mouldy and turns into acetic acid. 
Tartar emetic is an antimony potassium tartrate. Ro- 
chelle salt is a sodium potassium tartrate ; it is commonly 
used in medicine in the form of Seidlitz poivders. These 
are contained in a blue and a white paper. The former 

* Oxalic acid is made on a large scale from sawdust, soda, arid caustic potash. 
The woody fibre is resolved into oxalic acid, which combines with the bases, 
forming sodium and potassium oxalates. From these the acid is readily ob« 
tained. Sawdust will yield more than half its weight of crystals of this salt. 



THE ORGANIC ACIDS. 211 

holds 120 grains of Rochelle salt, and 40 grains of bicar- 
bonate of soda; the latter 35 grains of tartaric acid. They 
are dissolved in separate goblets. The one containing 
the acid is emptied into the other, when the C0 2 is set 
free, producing a violent effervescence and disguising the 
taste of the medicine. 

Malic Acid (C 4 H 6 5 ) occurs abundantly in most 
acid fruits, particularly in unripe apples, whence its name 
from malum, an apple. Citric acid (citrus, a lemon), the 
acid of the lemon, lime, etc., is often found associated 
with it, as in the gooseberry, raspberry, and strawberry. 
Citric acid is used in medicine as magnesium citrate. 

Tannic Acid [tannin (C 27 H 22 O l7 ) ] is found in the 
leaf and bark of trees.* — Example : Oak, hemlock. Nut- 
galls are excrescences which are formed by the puncture 
of an insect on the leaves of a certain species of oak. 
Tannin has an astringent taste, is soluble in water, and 
hardens albuminous substances, as gelatine. 

Ta?ming \ — After the hair has been removed from 
the skins by milk of lime, they are soaked for days, the 
best kinds for months, in vats full of water and ground 
oak or hemlock bark (tan-bark). The tannic acid of the 
bark is dissolved, and entering the pores of the skin, 
unites with the gelatine, forming a hard, insoluble com- 
pound which is the basis of leather. Leather is black- 
ened by washing the hide on one side with a solution of 
copperas. The tannic acid unites with the iron, forming 
a tannate of iron — an ink. In the same way, drops of 
tea on a knife-blade stain it black. 

* This astringent principle is widely diffused. There are several compounds 
which possess similar properties, yet differ in chemical composition. The tan- 
nin of the oak is called quercitannic acid; that of nut-galls, gaUotannic acid; 
that of tea, theitannic, and that of coffee, caffeotannic acid. 



212 ORGANIC CHEMISTRY. 

I?ik is made by adding a solution of nut-galls to one 
of copperas. The iron tannate thus formed has a pale 
blue-black color, as in the best writing-fluids ; by expos- 
ure to the air, the Fe absorbs more 0, the ink darkening 
in color until it is a deep black. Gum is added to thicken 
and regulate the flow of the fluid from the pen. Creo- 
sote or corrosive sublimate is used to prevent mouldiness. 
Steel pens are corroded by the free H 2 S0 4 contained in 
the ink, but gold pens are not affected by it.* 

Gallic Aczd (C 7 H 6 5 ) is associated with tannin in 
nut-galls, and can be formed from tannic acid. Pyrogal- 
lic acid can be obtained by the sublimation of gallic or 
gallotannic acid. It is extensively used in photography 
for the purpose of developing the latent image in the 
collodion film after exposure to the action of the light 
(See p. 167.) 



THE ORGANIC BASES. 

The organic bases, or alkaloids, as they are called, are 
the bases of true salts found in plants. They dissolve 
slightly in H 2 0, but freely in alcohol. They have a bit- 
ter taste, and rank among the most fearful poisons and 
valuable medicines. All the alkaloids contain N.f 



* The following is an instructive experiment, illustrating the manner of mak- 
ing ink, of removing stains with oxalic acid, and also the relative strength of the 
acids and alkalies. Take a large test-tube, and add the following reagents in 
solution, cautiously, drop by drop, watching the result and explaining the reac- 
tions: 1, iron sulphate (copperas); 2, tannic acid (tannin); 3, oxalic acid ; 4, 
sodium carbonate (sal-soda) ; 5, hydrochloric acid (muriatic) ; 6, ammonia 
(hartshorn) ; 7, nitric acid (aquafortis) ; 8, caustic potash ; 9, sulphuric acid (oil 
of vitriol). 

t A convenient antidote is tannin, which forms with nearly all of them insolu- 
ble curdy tannates. Almost any liquid containing it is of value— as strong, 



THE ORGANIC BASES. 213 

Opium is the dried juice of the poppy plant, which is 
extensively cultivated in Turkey for the sake of this pro- 
duct. Workmen pass along the rows soon after the 
flowers have fallen off, cutting slightly each capsule. 
From these incisions a milky juice exudes and collects in 
little tears. These are gathered and wrapped in leaves 
for the market. Opium contains six different alkaloids 
in combination with a single acid. In small doses, opium 
is a sedative medicine ; in larger ones, a narcotic poison. 
Laudanum is the tincture of opium; and paregoric, a 
camphorated tincture flavored with aromatics. 

Opium- e ating . — Opium produces a powerful influ- 
ence on the nervous system. It stimulates the brain and 
excites the imagination to a wonderful pitch of intensity. 
The dreams of the opium-eater are said to be vivid and 
fantastic beyond description. The dose must, however, 
be gradually increased to repeat the effect, and the result 
is most disastrous. The nervous system becomes de- 
ranged, and no relief can be secured save by a fresh 
resort to this baneful drug.* Labor becomes irksome, 

green tea. This is also of use as it tends to keep the patient awake, the great 
necessity in the case of a narcotic poison. 

* In time, the whole system becomes so impregnated with it that additional 
doses utterly fail to produce the delightful effect which at first so fascinated the 
victim. Then, while combining with the nerves, it set free a vast amount of 
vitality and force, but now it has satisfied itself. The subtle alkaloid has 
worked its way into the tissues and coatings of his entire internal organism. If, 
resolutely, he summons his enfeebled will, and commences the conflict, an agony 
of endurance, which defies all description, is before him. The whole body must 
be reorganized, and, atom by atom, the life-energy of the man must drag out of 
the flesh and blood the fearful poison. If, too weak to attempt so terrible a 
straggle, he continues the use of the fatal drug, he moves on directly to one fate, 
the opium-eater's grave. Paregoric, laudanum, morphine, and the different prep- 
arations of opium are in almost every case taken first as a sedative from pain or 
fatiguing labor, with no thought of becoming addicted to their use. Bat so 
insinuating is it that the victim forms the habit ere he is aware, and only know r s 
he is a slave when for some reason he attempts to cease the customary dose. 
No person can be too careful in the use of a narcotic whose influence is liable to 
become so destructive. 



214 ORGANIC CHEMISTRY. 

ordinary food distasteful, and racking pains torment the 
body. 

Morphine (Morpheus, the god of sleep) is one of the 
alkaloid bases of opium, and like it is used to alleviate 
pain and produce sleep. It is usually given as a sulphate 
or chloride. 

Quinine is prepared from Peruvian bark. A tincture 
of the bark, or sulphate of quinia, is employed in medi- 
cine in cases of fever and ague and other periodic dis- 
eases, and also as a tonic. 

Nicotine is the active principle of the tobacco plant, 
of which it forms from 2 to 8 per cent. It is volatile, 
and passes off in the smoke. A drop will kill a large dog. 
It probably produces many of the ill effects which follow 
the use of tobacco. 

Strychnine is prepared from the nux vomica and the 
St. Ignatius's bean. It is also a constituent of the cele- 
brated upas poison.* " It is so intensely bitter that one 
grain will impart a flavor to twenty-five gallons of water. 
One-thirtieth of a grain has killed a dog in thirty 
seconds, while half a grain is fatal to man." 

The Chromatic Test, as it is called, consists in plac- 
ing on a clean porcelain plate a drop of the suspected 
liquid, a drop of H 2 S0 4 , and a crystal cf potassium 
bichromate. Mix the three very slowly with a clean glass 
rod. If there be any strychnine present, it will change 
the color into a beautiful violet tint, passing into a pale 
rose.f 

* u The 'woorara,' with which the South American Indians poison . their 
arrows, is a variety of strychnine. This is so deadly that the scratch of a needle 
dipped in it will produce death; yet it maybe swallowed with impunity."— 
Milles. 

f Arsenic was once in favor with the poisoner, but Marsh's test infallibly re- 



THE ORGANIC BASES. 215 

Caffeine and Theine constitute the active prin- 
ciple of tea * and coffee, and are isomeric. They crystal- 
lize in long, flexible, silky needles. In addition, tea con- 
tains from 13 to 18 per cent, of a form of tannin (see p. 
211, note), about 15 per cent, of a nitrogenous substance 
allied to caseine,f and a volatile oil which gives to it its 
aromatic odor and taste. Coffee contains about 14 per 
cent, of a fixed oil, and also an essential oil which is 
developed in roasting, and is very volatile, so that it 
will soon escape unless the coffee be kept tightly cov- 
ered. 

veals its presence in the body of the victim, even after many years have elapsed. 
Tne organic poisons are so easily acted upon by the fluids of the system, that in 
one case, though four grains were taken, and death ensued very quickly, yet the 
"chromatic test' • failed to detect the presence of strychnine in the stomach. 
However, the murderer is not to escape. This is the only poison except brucite 
(and that also is extracted from nux vomica) that produces tetanus or lock-jaw. 
This symptom proves to the physician that death has been caused I v this alka- 
loid. To exhibit the effect of the poison a frog may be brought ix , 3 the court- 
room and made to show its action. So sensitive is this little animai that a few 
drops of oil containing only a hundred-thousandth of a grain of sti chnine will 
instantly throw it into a rigid locked-jaw, in which it is incapable f the least 
motion. 

* Tea-raising. — Tea-plants resemble in some respects the low v. lortleberry 
bush. They are raised in rows, [Uree to five in a hill, very much as < oru is with 
us, but they are not allowed to grow over one and a half feet high. Ti e medium- 
sized leaves are picked by hand, the !avc-e c< : or left T o f a voi eke growth 
of the bushes. Each little hill or clump will furnish from three to fr e ounces of 
green leaves, or about one ounce of tea, in the course of the season. The leaves 
are first wilted in the sud, then trodden in baskets by barefooted men to break 
the stems, next rolled by the hands into a spiral shape, then left in a heap to heat 
again, and finally dried for the market. This constitutes Blade Tea. and the 
color would be produced in any leaves left thus to wilt and heat in heaps in the 
open air. The Chinese always drink this kind of tea. They use no milk or 
sugar, and prepare it, not by steeping, but by pouring hot water on the :ea and 
allowing it to stand for a few minutes. Whenever a friend calls on a Chinaman, 
common politeness requires that a cup of tea be immediately offered him. 

Green Tea is prepared like black, except that it is not allowed to wilt or heat, 
and is quickly dried over a fire. It is also very frequently, if not always, colored 
— cheap black teas and leaves of other plants being added in large qua itities. In 
this country, damaged teas and the " grounds '* left at hotel* are highly 

colored, packed in old tea-chests, a~d sent out ~ 1 ... teas, certain varieties of 
black tea even receive a coating of black-lead to make them shiny. 

t This is lost in the '■ grounds." The Japanese, however, eat the tea-leaves, 
and bo save this nutritive part, 



216 ORGANIC CHEMISTRY. 



ORGANIC COLORING PRINCIPLES 

The organic coloring principles are generally of vege- 
table origin. They are found in the roots, wood, bark, 
flowers, and seeds of plants. 

'Dyeing . — Very few of the colors have such an affin- 
ity for the fibres of the cloth that they will not wash out. 
Those which, like indigo, will dye directly, are called sub- 
stantive colors. But the majority are adjective colors 
which require a third substance having an attraction for 
both the coloring matter and the cloth, to hold them to- 
gether. Such substances are called mordants (niordeo, to 
bite), because they bind the dye in the cloth, thus making 
a " fast color." The most common mordants are alum, 
tin oxide, and copperas. In dyeing, the cloth is first 
dipped into a solution of the mordant, and then into one 
of the dye-stuff. The mordant, by means of a stamp, 
may be applied to the cloth in the form of a pattern, and 
when it is afterward washed, the color will be removed 
except where the mordant fixed it in the printed figure. 
The same dye will produce different colors by a change 
of mordants. — Example : Madder with iron gives a fine 
purple, with alum a pink, and with iron and alum a 
chocolate. This principle lies at the basis of dyeing 
"prints."* 

* A calico-printing machine is very complex. The cloth passes between a 
series of rollers, upon which the corresponding mordant is put. as ink is on type. 
A single machine sometimes prints from twenty sets of rollers ; yet each im- 
pression follows the other so accurately, that when the cloth has passed through, 
the entire pattern is printed upon it with the different mordants more perfectly 
than any painter could do it, and so rapidly that a mile of cloth has been printed 
with four mordants in an hour. The cloth when it leaves the printing machine, 
though stamped with the mordants in the form of the figure, betrays nothing of 



ORGANIC COLORING PRINCIPLES. 217 

Coloring Substances .—Madder is the root of a plant 
found in the East, and extensively cultivated elsewhere. 
When first dug it is yellow, but by exposure it absorbs 
and becomes red. It is used in dyeing the brilliant Turkey- 
red. The coloring principle, which is named alizarine? is 
said to be identical with that derived from anthracene, a 
hydrocarbon found in coal-tar (see p. 208). Cochineal is a 
dried insect that in life lives upon a species of cactus 
in Central America. The coloring matter is called Car- 
mine. It yields the brightest crimson and purple dyes.* 
Brazil-wood furnishes a red which is not very permanent. 
It is used for making red ink. The indigo of commerce 
is obtained from a bushy plant found in the East 
Indies. By fermenting for some days in vats of water, 
the coloring matter is developed. Eeducing agents 
change indigo into a soluble and colorless substance by 
the absorption of H.f It is then called "white indigo." 
In this form it is extensively used in dyeing. The cloth 
becomes permanently colored on exposure to the air, when 
the insoluble blue indigo is formed in its fibres. Logwood, 
is so named because imported in logs. It is the heart 
of a South and Central American tree. With a mordant 
of alum it dyes black. Litmus is obtained from a 
variety of lichens common along the southern coast of 



the real design until after being dipped in the dye, which acting on the different 
mordants "brings out the desired colors. The print is now washed, glazed, and 
fitted for the market. 

* The purple of which we read in ancient writings was a secret with the 
Tyrians. King Huram, we learn, sent a workman to Solomon skilled in this 
art. The dye was obtained from a shell-fish that was found on the coast of 
Phoenicia. Each animal yielded a tiny drop of the precious liquid. " A yard c£ 
cloth dipped twice in this costly dye was worth $150." 

t Dissolve a little indigo in strong H ? S0 4 . Color a test-tube of H 2 with the 
solution. Add a drop of HN0 3 , and on gently heating, the color will disar> 
pear. 

10 



218 ORGANIC CHEMISTRY. 

Europe. Its juice is colorless, but on the addition of 
H 3 N it assumes a rich purple blue. Leaf -green (chloro- 
phyll), as found in plants, is a resinous substance con- 
taining several coloring matters. It seems to be devel- 
oped by the action of the sunbeam. Plants removed from 
a dark cellar to the sunlight rapid! v turn green. 



THE OILS AND FATS. 

The oils and fats are derived from both the vegetable 
and the animal kingdom. They are divided into two 
classes — fixed and volatile. The former make soaps, the 
latter do not. The former, when' heated above 500°, give 
off acrid and offensive vapors ; * the latter may be distilled 
without alteration.! 

1. THE FIXED OILS. 

Composition.— The fatty bodies are salts, being 
compose! of stearin, palmitin, and olein.% These consist 
of three acids, stearic, palmitic, and oleic, combined with 
a common base — glycerin. 

The first two of these salts are solids at common 
tempera ures, and form fats ; the last is a liquid, and 
forms oils. The relative proportion of olein contained 

* At a higher temperature they are decomposed, and among the products is an 
acrid substance (acrolein) with wbicn we are familiar in the disagreeable smell 
of a smouldering candle-wick and in burning fat. 

t " The former produce a permanent stain on paper, the latter do not. A cork 
twisted into the neck of a bottle containing a fixed oil makes no noise * in a 
volatile oil it squeaks." 

X Stearin, from stear, suet : palmitin, since it is abundant in palm oil ; olein, 
from oleum, oil ; glycerin, from giukeros, sweet. 



THE FIXED OILS. 219 

in any fatty substance determines its fluidity. — Example : 
Stearin is abundant in tallow, and palmitin in butter; 
hence their comparative consistency. Lard, on the other 
hand, contains so much olein that it is expressed as 
" lard-oil." Olive-oil contains much olein and palmitin ; 
the former remains fluid at ordinary temperatures, but 
the latter, in cold weather, hardens into a thick deposit, 
and renders the oil viscid. 

Glycerin (C 3 H 8 3 ) is an cdorless, transparent syrup. 
It is soluble in H 2 and alcohol. On account of its 
healing properties its use is common in dressing wounds, 
insect bites, chapped hands, etc. 

By the action of HN0 3 and H 2 S0 4 glycerin is con- 
verted into nitro-glycerin [C 3 H 5 (N0 2 )30 3 ], an oil that 
often explodes with fearful violence by a slight concussion. 
Dynamite, used in blasting, is powdered silex, or infusorial 
earth {Geology, p. 48), saturated with glycerin. 

Soap. — If sweefc-oii and H 2 be placed in a test-tube 
and shaken, they will mix but not unite: for on standing, 
the oil will rise to the top. Add, however, caustic potash 
or a little "lye" (see p. 128), when, on heating, a clear, 
soapy solution will be formed. The K of the alkali has 
combined with the oleic and palmitic acids of the oil, 
making two new salts — potassium oleate and potassium 
palmitate ; while the expelled glycerin remains floating 
in the liquid. 

The manufacture of soap is based on this principle. A 
variation in the alkaline base and the fat or oil used, pro- 
duces the different kinds of soap. Potash, on account of 
its affinity for H 2 0, forms soft-soap. Soda* is not deli- 

* A deliquescent snbstance is one which dissolves in H a O, which it absorbs 
from the air. 



%%0 ORGANIC CHEMISTRY. 

quescent, and hence makes hard-soap.* Lard forms a 
softer soap than tallow. Castile soap is made from olive 
oil and soda. Its mottled appearance is due to the 
coloring matter which is stirred through it while it is 
yet soft. Home-made soap is prepared by boiling " lye " 
and " grease." f As the latter contains such a variety 
of fatty substances the soap generally consists of the 
three salts — potassium oleate, palmitate, and stearate. 
Yellow soap contains some resin in place of fat. Cocoa- 
nut-oil makes a soap which will dissolve in salt water, 
as it contains an excess of alkali. Soap-balls are made 
by dissolving soap in a very little water, and then work- 
ing it with starch to a proper consistency to be shaped 
into balls. White toilet-soaps are made from lard and 
soda. The curdling of soap in hard water is caused by 
the formation of a calcium or a magnesium soap which 
is insoluble in H 2 0, and floats on the top as a greasy 
scum. J 

The Cleansing Qualities of Soap . — There ex- 
udes constantly from the pores of the skin an oily per- 
spiration, and this catching the floating dust dries into a 
film which will* not dissolve in H 2 0. The alkali of the 
soap combines with this oily substance and makes a solu- 
ble soap. In addition, the alkali also dissolves the cuticle 
of the skin, and thus produces the " soapy feeling/' as we 
.term it, when we handle soap. 

* Soap is frequently adulterated with gypsum, lime, pipe-clay, or sodium 
silicate. These may he detected "by dissolving a piece of the soap in water or 
alcohol, and noticing if there he any precipitate. 

t The heat hastens the chemical change, which takes place more slowly in 
making what is known as " cold soap." 1 

% A soap made from lard, in water containing calcium carbonate, would un- 
dergo the following reaction : Potassium oleate + calcium carbonate = calcium 
oleate + potassium carbonate. 



THE FIXED OILS. 221 

Saponification (sapo, soap ; facere, to make) is the 
process of separating the fatty acids and glycerin, and is 
so named even when no soap is formed. One method is 
as follows : Tallow or lard is boiled with lime, and thus 
made into a calcium soap. This is decomposed by H 2 S0 4 , 
forming calcium sulphate, which, being insoluble, sinks 
to the bottom, leaving the three acids of the fat floating 
upon the surface.* The glycerin is also left by itself in 
the liquid, from whence it is removed and prepared for 
the market. The acids, when cool, are subjected to great 
pressure ; the oleic flows out, leaving the stearic and pal- 
mitic acids as a milk-white, odorless, tasteless solid, which 
is commonly called stearin, and extensively used in the 
manufacture of stearin or adamantine candles. f 

Wax is found in nearly all plants. It forms the shiny 
coating of the leaves and fruit. — Example : Lemon leaf, 
apple. Certain plants in Japan contain so much wax 
that it is separated by boiling and used for making can- 
dles. Bees, even when fed on sugar alone, have the 
power of converting it into wax, which is therefore to be 
regarded as an animal secretion. — Millee. Beeswax is 
bleached by exposure to the air in thin ribbons. 

Z/inseed Oil is a drying oil, as it is termed — i. e., it 

* Fat is also decomposed by tbe action of superheated steam, which at once 
liberates the fatty acids. 

t Paraffine candles are made from coal-oil. Wax candles are manufactured by 
the following process : A large number of cotton wicks are hung upon a revolv- 
ing frame with projecting arms. The wicks are fitted at the ends with metal 
tags to keep the wax from covering that part. As the machine slowly turns, a 
man, standing ready with a vessel of melted wax, carefully pours a little upon 
each wick in succession. This process is repeated until the candles reach the 
desired size. They are then rolled on a smooth stone slab, the tops cut by 
conical tubes, and the bottoms trimmed, when they are ready for use. The large 
tapers burned in Catholic cathedrals are made by placing the wick on a sheet of 
wax, rolling it up till the right thickness is reached, when the candle is trimmed 
and polished as before. Spermaceti candles are run from the white, crystalline, 
solid fat which is found with sperm oil in the head of the sperm whale. 



822 ORGANIC CHEMISTRY. 

absorbs from the air,* and hardens by exposure. It is 
expressed from flaxseed, which furnishes about one-fifth 
of its weight in oil. Boiled oil is made by heating the 
crude oil with litharge, which entirely dissolves and 
greatly increases the drying property of the oil. Linseed 
oil is used in mixing paints and varnishes. Putty con- 
sists of linseed oil and whiting well mixed. Printers' ink 
is made by heating linseed oil until it becomes thick and 
viscid, when lampblack is added to give it the proper 
consistency. 

Cod-2i?ser Oil is extracted from the liver of the cod- 
fish. It contains I, Br, and P, and is much used as a 
remedy in consumption. 

Croion Oil is made from the seeds of an Indian 
plant ; it is a powerful medicinal agent, 

Casio?* Oil is extracted from the castor-oil bean. It 
is used in medicine, and also in perfumery and hair-oils. 

Sweet or Olive Oil is expressed from the olive fruit. 
It is an unctuous oil, i. e., it absorbs on exposure to the 
air— not hardening like the drying oils, but remaining 
sticky, and after a time becoming rancid, f In the south- 
ern part of Europe, olive-oil is extensively used as an 
article of food. 

2. THE VOLATILE OILS. 
The volatile oils, unlike the fixed, make no soaps, and 

* This absorption of O is sometimes so rapid as to be attended by sufficient 
heat to occasion the mass to take fire ; and several serious conflagrations have 
been traced to such spontaneous combustion. (See p. 93.) 

t This change is attended by a slight absorption of O, and appears to he due 
to the decomposition of certain mucilaginous and albuminous matters, which, 
during their decay, react on the fat. setting free the fatty acids, and decomposing 
the glycerin. Perfectly pure fats and oils do not become rancid. 



THE VOLATILE OILS. 

dissolve readily in alcohol or ether. Their solution in 
alcohol forms an essence. 

Sources. — The volatile or essential oils are of vegetable 
origin, They are found in the petals of a flower, as the 
violet; in the seed, as caraway; in the leaves, as mint, 
or in the root, as sassafras. Sometimes several kinds of 
oil are obtained from different parts of the same plant. — 
Example : In the orange tree, the flower, leaves, and rind 
of the fruit furnish each its own variety. The perfume 
of flowers is produced by these volatile oils; but how 
slight a quantity is present m ay . inferred from the 
statement that " one hundred pounds of fresh roses will 
give scarcely a quarter of an ounce of Attar of Boses." 

Preparation, — In the peppermint, the wintergreen, and 
many others, the plant is distilled with water. The oils 
pass over with the steam, and are c rndensed in a refrig- 
erator connected with the u Mint Still/* 5 The oil floats 
on the surface of the condensed water, and may be 
removed. A small portion, however, remains mingled 
with the latter, which thus acquires its peculiar taste and 
odor, constituting what is termed a " perfumed water/* 
In some flowers, as the violet, jasmine, etc., the perfume 
is too delicate to be collected in this manner. They are 
therefore laid between woollen cloths saturated with 
some fixed oil. This absorbs the essential oil, which is 
then dissolved by alcohol. The oil of lemon or orange is 
obtained from the rind of the fruit by expression or by 
^digesting in alcohol. 

Composition. — C i0 H, 6 is the common symbol of a large 
number of these oils. Thus the oils of lemon, cloves, 
juniper, birch, black pepper, ginger, bergamot, turpen- 
tine, cubebs, oranges, etc., nearly twenty in all, are iso- 



22J+ ORGANIC CHEMISTRY. 

meric. They are pure hydrocarbons. A second class 
contains 0, and a third S. 

First Class of Volatile Oils. — The oil of tur- 
pentine (C, H j6 ) is a type of this division. It is made by 
distilling pitch with H 2 0. It is generally called spirits 
of turpentine. It is highly inflammable, and, owing to 
the excess of C, burns with a groat smoke. By the union 
of two atoms of its H with an atom of the of the air to 
form H 2 0, it is converted into rosin.* Camphene is tur- 
pentine purified by repeated distillation. Burning-fluid, 
is a mixture of camphene and alcohol. In the heat of 
the burning H of the latter, the C of the former is con- 
sumed, and this produces a bright light. The tendency 
of camphene to smoke is thus diminished, and the illu- 
minating power increased. By the action of HC1 on tur- 
pentine or oil of lemons an artificial camphor is produced 
which much resembles common camphor. 

TJie Second Class includes camphor, the oils of 
bitter almonds, cinnamon, spearmint, wintergreen, etc. 
Camphor (C, H| 6 0) is obtained by distilling the roots and 
leaves of the camphor-tree with water, and condensing 
the vapors on rice-straw. It is purified by sublimation. 
When kept in a bottle, it vaporizes, and its delicate crys- 
tals collect on the side toward the light. Taken inter- 
nally, except in small doses, it is a virulent poison. Its 
solution in alcohol is called "spirits of camphor." If H 2 
be added to this, the camphor will be precipitated as a 
flour-like powder, f 

* In this way, the turpentine around the nozzle of a bottle in which it is 
kept "becomes first sticky and then resinous. Old oil should not be taken to 
remove grease spots, as, while it will remove one, it will leave another of its 
own. 

t Though camphor gum is powdered with difficulty, a few drops of alcohol will 



RESINS AND B AL SAMS. Z2d 

The Third Class includes garlic, assafoetida, onions, 
mustard, horse-radish,* etc. They are known for their 
pungent taste and the disagreeable odor they often im- 
part to the breath, f 



THE RESINS AND BALSAMS. 

The resins are generally formed from the essential oils 
by a slow oxidation. — Example: Turpentine, as we 
have just seen, is changed to rosin, a resinous substance. 
If the resin is dissolved in some essential oil, it is called a 
balsam. — Example : Pitch is a true balsam, since by dis- 
tillation it is separated into rosin and turpentine. They 
generally exude from incisions in trees and shrubs, in the 
form of a balsam, which oxidizes on exposure to the air, 
and becomes a resin. — Example: Spruce gum. The 
resins are translucent or transparent, brittle, insoluble in 
H 2 0, but soluble in ether, alcohol, or any volatile oil, and 
form varnishes. They are non-conductors of electricity, 
and burn with much smoke. They do not decay, and, 
indeed, have the power of preserving other substances. J 

SSoszn constitutes about 75 per cent, of pitch, a resin- 
ous substance which exudes from incisions made in the 

remove all trouble. When small particles of powdered camphor are thrown on 
water free from grease, each fragment begins to dissolve with a remarkable gyra- 
tory motion, which is instantly checked by a drop of an essential oil allowed to 
fall upon the surface of the liquid. 

* The essential oil of garlic, onions, etc., is the sulphide of allyl, a radical hav- 
ing the formula C 3 H 5 : the oil of horse-radish is the sulpho-cyanide of allyl. 

t The oil of mustard is not contained in the seed, but is formed in it by the 
action of water and a latent ferment. This is the reason why mustard, when 
first prepared for the table, is bitter, but becomes pungent after a little time. 

% For this reason they were used in embalming the bodies of the ancient 
Egyptians, which, after the lapse of two thousand years, are yet found dried into 
mummies in their mammoth tombs— the Pyramids, 



226 ORGANIC CHEMISTRY. 

trunks of certain species of pine. It is used in making 
soaps, to increase friction in violin-bows and the cords 
of clock- weights, and in soldering. 

JjCte exudes from the ficus-tree of the East Indies. 
An insect punctures the bark, and the juice flows out 
over the insect, which works it into ceils in which to 
deposit its eggs. The dried gum incrusting the twigs is 
called dick-lac ; when removed from the wood, seed-lac ; 
when melted and strained, shellac. The liquefied resin 
is dropped upon large leaves, and so cools in broad, thin 
pieces. Sealing-wax is made of shellac and Venice tur- 
pentine; vermilion being added to give the red color. 
Shellac is much used in making varnishes. 

Gum Senzoin also exudes from a tree in the East 
Indies. It is the principal source of benzoic acid. It is 
used in fumigation and in cosmetics, and on account of 
its fragrant odor is burnt as incense.* 

Amber is a fossil resin which has exuded in some 
past age of the world's history from trees now extinct. 
It is sometimes found containing various insects perfectly 
preserved, which were without doubt entangled in the 
mass while it was yet soft. These are so beautifully 
embalmed in this transparent glass that they give us a 
good idea of the insect life of that age. Amber is cast 
up by the sea, principally along the shores of the Baltic ; 
although it is also found in beds of lignite. It is com- 
monly translucent, and susceptible of a high polish. It 
is used for ornaments, mouth-pieces, necklaces, buttons, 
etc, ; and is an ingredient of carriage varnish. 

* Place some green sprigs under a glass receiver, and at the bottom a hot iron, 
on which sprinkle a little benzoic acid. It will sublime and collect in beautifully 
delicate crystals on the green leaves above, making a perfect illustration of win* 
ter frost-work. 



BE SINS AND BALSAMS. 227 

CaoulcJiotic or Z7idia-r ubber (zC 5 H 8 ) is a mix- 
ture of several hydrocarbons. It exudes from certain 
trees in South America as a milky juice.* The solvents 
of rubber are ether, naphtha, turpentine, chloroform, bi- 
sulphide of carbon, etc. It melts, but does not become 
solid on cooling, Freshly-cut surfaces readily cohere i 
this property, together with its power of resisting most 
reagents, renders it invaluable to the chemist in making 
flexible joints and tubes. " It loses its elastic power when 
stretched for a long time, but recovers it on being heated. 
In the manufacture of rubber goods for suspenders, etc., 
the rubber thread is drawn over bobbins and left for some 
days until it becomes inelastic. In this state it is woven, 
after which a hot wheel is rolled over the cloth to restore 
the elasticity." 

Vulcanized Stibbe?* is made by heating caoutchouc 
with a sman amount ui sulphur. This constituted Good- 
year's original patent. f It is less liable to be hardened 

* The globules of rubber are suspended in it as butter is in milk. By adding 
H 3 N the sap may be kept unchanged for months, and is sometimes exported in 
that form preserved in rightly corked bottles. The tree, it is said, yields about 
a gill per day from each incision made. A little clay cup is placed underneath, 
from which the juice is collected and poured over clay or wooden patterns in 
successive layers as it dries. To hasten the process it is carried on over large 
open fires, the smoke of which gives to the rubber its black color ; when pure it 
is almost white. When nearly hard, the rubber will receive any fanciful design 
which may be marked upon it with a pointed stick. The natives often form the 
clay into odd shapes, as bottles, images, etc., and the rubber is sometimes ex- 
ported in these uncouth forms. 

t Mr. Goodyear had been experimenting to find some way of rendering rubber 
insensible to heat and cold. It is said that one day, while talking with a friend, 
he happened to drop a bit of S in a pot of melted rubber. By one of those happy 
intuitions which seem to come only to men of genius, he watched the process, 
and to his amazement found that while the appearance of the rubber was the 
same— elastic, odorous, and tasteless — its stickiness was gone, and it had gained 
the properties he so much desired. He immediately took out a patent in this 
country and sailed for England, where, instead of securing his secret by a simi- 
lar patent, he offered to sell it for £10,000. Charles Hancock, with whom he had 
been corresponding for several years, and who had been engaged in similar 
experimenting, resolved to discover it himself, He shut himself up in his labo- 



ORGANIC CHEMISTR Y. 

by cold or softened by heat, and admits of many uses to 
which common rubber would be entirely unsuited. If 
sulphurized rubber be heated to a high temperature it 
becomes a hard, brittle, black solid, capable of a high 
polish, which is used for knife-handles, combs, buttons, 
etc. 

6rtt£ta-jjerc/ia (C 2 oH 32 ) resembles caoutchouc in its 
source, preparation, and appearance. It softens in warm 
water, and can then be moulded like wax. When cooled 
it assumes its original solidity. It is extensively used 
in taking impressions of medals, etc. 



THE ALBUMINOUS BODIES. 

These are albumen, casein, gelatin, and fibrin. Owing 
to the complexity of their composition, no satisfactory 
formula can be assigned to them. The molecule of albu- 
men has been stated as C 7 2H no N, 8 S0 2 2? but it is very 
uncertain.* 

Mbumen is found nearly pure in the whites of eggs \ 
— hence the name (albus, white). It exists in two amor- 
phous conditions — as a liquid in the sap of plants, the 
humors of the eye, serum of the blood, etc. ; and as a 

ratory and went to work. Disheartening failures marked every attempt. At 
last he tried S. At first, he did not succeed ; but, persevering, he finally saw, 
amid the stifling fumes of brimstone, the soft rubber metamorphosed into the 
vulcanized caoutchouc. He, too, was possessed of the secret, and, taking out a 
patent, reaped the reward of his patient labor. 

* Many chemists regard albumen, casein, fibrin, etc., as chemically identical 
and capable of being converted by the vital force one into the other. These 
bodies are sometimes called Protein {protos, first) on the supposition that they 
were derived from a single azotized principle named protein. 

t Strange to say, " the venom of the rattlesnake is isomeric with the ' whites 
of eggs.' " 



THE ALBUMINOUS BODIES. 

solid in the seeds of plants, and the nerves and brains of 
animals.* 

Properties. — It is soluble in cold, but insoluble in hot 
H 2 0. At a temperature of about 140° F. it coagulates. 
This change we always see in the cooking of eggs ; yet 
nothing is known of its cause. Alcohol, corrosive subli- 
mate, acids, creosote, and solutions of copper, lead, silver, 
etc., have the power to coagulate albumen. In cases of 
poisoning by these substances, the white of eggs is there- 
fore a valuable antidote, as it wraps them in an insoluble 
covering, and so protects the stomach. 

Casein (caseus, cheese) is found in the curd of milk. 
In the presence of an acid it coagulates, and thus milk 
curdles after it sours. Eennet (the dried stomach of a 
calf) is used to coagulate milk in the process of cheese- 
making, but the cause of its action is not understood. 

Milk is a natural emulsion, composed of exceedingly 
minute globules diffused through a transparent liquid. 
The globules consist of a thin envelope of casein filled 
with butter. Being a trifle lighter than H 2 0, they rise 
to the surface as cream. Churning breaks these cover- 
ings, and gathers the butter into a 
mass. Milk contains some sugar, 
which by a peculiar change termed 
" lactic fermentation " is converted 
into lactic acid. The casein seems to 
act as a ferment in hastening this 
oxidation, and by its decay produces 

the offensive Odor. In the " SOUr- MilJc under the Microscope. 



* This principle is of very great importance, as albumen may thus be carried 
by the blood through the system, but when once deposited it cannot be dissolved 
and washed away again. 




280 ORGANIC CHEMISTRY. 

ing " of milk there is no extrication of gas and no absorp- 
tion of 0. The milk-sugar (C, 2 H 2 4.0,2) disappears and 
lactic acid (C 3 H 6 3 ) gradually takes its place. It is an 
excellent illustration of a complex molecule breaking up 
into simple ones. 

Gelatin . — Hot water dissolves a substance from ani- 
mal membranes, skin, tendons, and bones,* which, on 
cooling, forms a yielding, tremulous mass called gelatin. 
In calves-foot jelly, soups, etc., it is well known. f Glue 
is a gelatin made from bones, hoofs, horns, etc., by boil- 
ing in H 2 and then evaporating the solution. Isinglass 
is a very pure gelatin, obtained from the air-bladders of 
the cod, sturgeon, and other fish. Size is a gelatin pre- 
pared from the parings of parchment. It is used for 
sizing paper in order to fill up the pores and prevent the 
ink from spreading, as it does on unsized or blotting- 
paper. 

J^ibrin constitutes chiefly the fibrous portion of the 

* Bones consist of organic and mineral matter combined. 
Analysis. (Berzelius.) 

Gelatin 32.17 

Blood-vessels 1.13 

Phosphate of lime 51.04 

Carbonate of lime 11.30 

Fluoride of calcium 2.00 

Phosphate of magnesia 1.16 

Chloride of sodium 1.20 

100.00 

By soaking a bone in HC1 the mineral matter will all be dissolved, and the 
organic matter left in the original shape of the bone, but soft and pliable. If, 
instead, the bone be burned in the fire, the organic matter will be removed and 
the mineral left white and porous. (See Physiology, p. 20.) 

t As an article of food it is of very little nutritive value. It may answer to 
dilute a stronger diet, but of itself does little to build up the body of an invalid. 
Beef-tea, even, is now thought to have little nourishing property, its principal 
omce being to act as a stimulant. 



THE ALBUMINOUS BODIES. 



231 




Fibrin, or Muscle. 



muscles. If a piece of lean Fi 9- 7U - 

beef be washed in clean H 2 
until all the red color disap- 
pears, the mass of white tis- 
sue which will remain is 
called fibrin. Like albumen, 
it exists in two forms — as a 
liquid in the blood, and as a 
solid in the flesh. The clot- 
ting of blood is due to the coagulation of the fibrin. 
(See Physiology, p. 108.) 

Vegetable Albuminoids . — Vegetables contain sub- 
stances which are scarcely to be distinguished from the 
albuminous bodies deriyed from animal sources. If wheat 
flour be made into a dough, and then kneaded in water 
until the soluble portion is washed away, the tough, 
sticky mass which will remain is called gluten. It is a 
nitrogenous substance, allied to albumen. It exists most 
abundantly in the bran of cereal grains. 

By treating peas as w r e do potatoes in forming starch, 
and then adding a little acid to the water which is left 
after the starch settles, an albuminous substance is depos- 
ited, which is thought to be identical with casein. The 
Chinese use it largely for cheese. It is found abundantly 
in the seeds of peas, beans, etc., and is termed legumin. 

'Putrefaction . — Owing to the complex structure of 
albuminous substances, and the presence of N, they read- 
ily oxidize and form new and simple compounds. This 
breaking up of the organic structure is called putrefac- 
tion. Any albuminous substance thus putrefying may 
act as a ferment. This probably explains the danger 
physicians incur in dissecting a dead body. The least 



282 ORGANIC CEE31ISTRY. 

portion of the decomposing matter entering the flesh, 
through a scratch even, is liable to be fatal. The absence 
of H 2 retards chemical change, and therefore, meats, 
apples, etc., are preserved by drying.* Salt acts somewhat 
in the same way by absorbing the juice of the meat, and, 
while it covers it as brine, wards off the attacking ; but 
as it dissolves some of the salts and other valuable ele- 
ments, it makes the meat less nutritious. 



DOMESTIC CHEMISTRY. 

1^ the chemistry of housekeeping there are some 
points not yet mentioned, which may now be profitably 
discussed. 

Making !Bread. — Flour consists of gluten, starch, 
and a little dextrine and sugar. 

The oily matter and the salts — of which there are from 
one to two per cent, in wheat — are contained mainly in 
the bran. The process of mixing the " sponge " is purely 
mechanical. When the sponge is set in a warm place to 
rise (as heat favors chemical change), the yeast, yeast- 
cake, or emptyings, f as the case may be, induces a rapid 

* The cold also protects from chemical change. The bodies of mammoths 
have been found in the frozen soil of the Arctic regions so perfectly preserved 
that the dogs ate the flesh. How long the animals had been there we cannot tell, 
but certainly for ages. In 1861 the mangled remains of three guides were found 
at the foot of the Glacier de Boisson, in Switzerland. They had been lost in an 
avalanche on the plateau of Mont Blanc, forty-one years before. 

t Milk-emptyings are sometimes used in making bread. In this case, the 
mixture of flour and milk, kept at a temperature of about " blood heat," rapidly 
develops yeast, which produces fermentation. If the heat is much above this, 
the plant will be killed, and the milk be merely turned to lactic acid. Often- 
times, too, the side of the di«h, near the fire, may be warm enough to produce 
yeast and to generate CO.. and alcohol, while on the opposite side lactic acid 
is being formed. A uniform temperature is necessary, and this can best be ob- 



DOMESTIC CHEMISTRY. 233 

fermentation, converting the sugar into alcohol and C0 2 . 
This gas is diffused through the mass, and being retained 
by the tenacious and viscid dough, causes it to "rise/ 5 L e., 
to swell and become porous. The next step includes the 
addition of fresh flour, and a laborious process of " knead- 
ing." The latter, so essential to good bread, diffuses the 
half -fermented sponge uniformly through the dough ; it 
also breaks up into smaller ones the bubbles of gas entan- 
gled in the gluten, and thereby makes the bread fine- 
grained. The dough is now " moulded " into loaves, and 
then placed in the oven. The heat rapidly expands the 
CO 2 ? and increases the porosity of the bread. The starch 
granules are broken up and the alcohol vaporized, and, 
with a part of the H 2 0, driven off. The surface gradually 
becomes dry and hard, and losing a part of its chemically 
combined water, is partially converted into a substance 
allied to caramel, thus forming the crust.* If the tem- 
perature of the oven is right, the cells of the bread will 
have sufficient strength to retain their form after the gas 
and vapors have escaped. If the heat is not sufficient, or 
if there is too much water in the dough, the C0 2 escapes, 
the cells, not being sufficiently hardened, collapse, and 
the bread is " slack-baked/' If the oven is too hot, the 
crust forms too quickly over the surface of the loaf, pre- 
venting the escape of the C0 2 , which accumulates at the 
centre, making the bread hollow. 

Stale "Bread. — New bread consists of nearly one- 
half water. In stale bread this disappears. It has, how- 

tained by placing the dish of emptyings in a kettle of warm water on the stove 
hearth. 

* A shiny coat is given to the loaf ("rusk") by moistening the crust after the 
bread is baked, thus dissolving some of the dextrine, which is also contained in 
the crust. This quickly dries on returning it to the oven. 



284 ORGANIC CHEMISTRY. 

ever, only chemically combined with the solid portions, 
and may be brought to view by heating the loaf in a close 
tin vessel. 

jle7*ated '33 re ad is made in the following manner : 
Flour and salt are put in a revolving copper globe, into 
which H 2 charged with C0 2 is admitted. When well 
mixed, a stop-cock is turned and the dough is driven out, 
by the elastic force of the gas, into pans ready for 
baking. 

Sour !B?*ead results from a neglect to arrest the first 
stage of the fermentation, thus allowing the second stage 
to commence and acetic acid to be formed. . The acid is 
neutralized by an alkali, as saleratus, or soda. 

Gi'iddle-cakes are raised by the addition of some 
ferment, as yeast ; but the second, or acetic stage, is 
always reached. The " batter " then tastes sour, and is 
sweetened by saleratus or soda. The acetic acid combines 
with the metallic base, forming a harmless salt which 
remains, while the C0 2 bubbles up through the batter, 
making it " light." 

Hiaisi?ig ^Biscuit. — In raising biscuit or cake, soda 
and cream of tartar * are most commonly used. The 
C0 2 is set free, and, escaping as a gas, makes the dough 
porous, while the sodium and potassium tartrate (Eochelle 
salt) which is left is a simple salt. Ordinary " baking- 
powders " are merely cream of tartar and soda. A variety 
invented by Prof. Horsford contains acid calcium phos- 
phate (see note, p. 140) ; this reacting upon the "soda" 
forms calcium and sodium phosphates, both of which are 



* Cream of tartar is often adulterated with plaster, lime, chalk, or flour. By 
dissolving in water, these impurities can be detected, as they form an insoluble 
precipitate ; "but in milk as commonly used in cooking, they are not noticed. 



DOMESTIC CHEMISTRY, 235 

materials for bone-making.* Soda and HC1 are also used 
in baking. By heat both constituents are resolved into 
H 2 0, CC 2 . and NaCl. The H 2 and C0 2 raise the bread, 
while the common salt seasons it. There is a difficulty 
in procuring pure acid and in mixing the ingredients in 
their combining proportions. Sal-yolatile (ammonium 
sesquicarbonate, p. 135) is often used by bakers for raising 
cake. This should volatilize into two gases, H 3 N and 
C0 2 , on the application of heat, but in practice a portion 
is commonly left hidden in the cake, and may be detected 
by the odor. Alum is often employed by bakers to 
whiten bread and render the gluten of inferior flour 
more tenacious. 

Toasting Hiread. — By toasting, bread becomes 
much more digestible, as the starch is converted largely 
into dextrine, which is soluble. The charcoal which may 
be formed when the heat has disorganized the bread and 
driven off the water, also acts favorably on the stomach 
by absorbing in its pores noxious gases, as in " crust- 
coffee." 

CooM?ig "Potatoes. — A raw potato is indigestible, 
but by cooking, the starch granules absorb the water of 
the potato, burst, and make it " mealy." If the potato 
contains more H 2 than the starch can imbibe, it is called 
" watery." 



* It is doubtful whether ordinary yeast-powders or cream of tartar and soda 
make as healthy food as the regular process of fermentation. There is fre- 
quently a portion of the powders left uncombined, and always a salt formed 
which may perhaps interfere with the action of the gastric juice. Sometimes, 
indeed, we find biscuit and cake yellow, and even spotted with bits of saleratus: 
yet, through a false economy, such food is too often " eaten to save it." 



286 ORGANIC CHEMISTRY. 



PRACTICAL QUESTIONS. 

1. How would you prove the presence of tannin in tea? 

2. How would you test for Fe in a solution ? 

3. Why can we settle coffee with an egg ? 

4. How would you show the presence of starch in a potato ? 

5. Why is starch stored in the seed of a plant ? 

6. Why are unbleached cotton goods dark -colored ? 

7. Why do beans, rice, etc., swell when cooked? 

8. Why does decaying wood darken ? 

9. Why does smoke cure hams ? 

10. How would you show that C exists in sugar ? 

11. Why do fruits lose their sweetness when over-ripe? 

12. Why does maple-sap lose its sweetness when the leaf starts ? 

1 3. Should yeast cakes be allowed to freeze ? 

14. Why will wine sour if the bottle be not well corked ? 

15. Why can vinegar be made from sweetened water and brown 
papei ? 

16. Why should the vinegar-barrel be kept in a warm place ? 

17. Why does " scalding" check the " working" of preserves ? 

18. Is the oxalic acid in the pie-plant poisonous ? 

19. How may ink- stains be removed ? 

20. Why is leather black on only one side ? 

21. Why do drops of tea stain a knife-blade ? 

22. Why will not coffee stain it in the same way ? 

23. Why does writing-fluid darken on exposure to the air ? 

24. What causes the disagreeable smell of a smoldering wick ? 

25. Why does ink corrode steel pens ? 

26. How does a bird obtain the CaC0 3 for its egg shells ? 

27. Why will tallow make a harder soap than lard ? 

28. Why does new soap act on the hands more than old ? 

29. What is the shiny coat on certain leaves and fruits ? 

30. Why does turpentine burn with so much smoke ? 

31. Why is the nozzle of a turpentine bottle so sticky ? 

32. Why does kerosene give more light than alcohol ? 

33. What is the antidote to oxalic acid ? Why ? 

34. Would you weaken camphor spirits with water? 

35. What is the difference between rosin and resin? 

36. Why does skim-milk look blue and new milk white ? 

37. Why does an ink-spot turn yellow after washing with soap ? 



CONCLUSION. 287 



CONCLUSION. 

Chemistry of the Sunbeam. — The various plant, 
products of which we have spoken in Organic Chemistry, 
when burned, either in the body as food or in the air as 
fuel, give off heat. This was garnered in the plant while 
growing, and came from that great source of heat— the 
sun. Thus all vegetation contains the latent heat of the 
sunbeam, ready to be set free upon its own oxidation. 
The coal, even, derived as it is from ancient vegetation, 
hidden away in the earth, is thus a mine of reserved 
force. Those black diamonds we use as fuel become, in 
the eye of science, crystallized sunbeams, fagots of force, 
ready to impart to us at any moment the heat of some 
old Carboniferous day. A field of growing w^heat reaches 
out its tiny arms, and tangling in stalk and grain the 
heat of sultry mid-summer, retains it against the bleak 
December. The oil-well spouts not alone unsavory 
kerosene, but liquid sunbeams, the gathered store of a 
geologic age. As we warm ourselves by our fires, or sit 
and read by our oil and gas lights, how strange the 
thought that their light and heat streamed down upon 
the earth ages ago, were absorbed by the grotesque leaves 
of the old coal forests, and kept safely stored away by a 
Divine care, in order to provide for our comfort ! The 
present warmth of our bodies all came from the same 
source — the sun. It mostly fell in the sunbeams of last 
summer upon our gardens and fields, was preserved in 
the potatoes, cabbage, corn, etc., we have eaten as food, 



288 CONCLUSION. 

and to-day reappears as heat and motion. Every blow, 
every breath, and every step, are but transformations of 
solar rays and can be estimated in sunshine. 

The Sun the Sotirce of *Powe?\ — The Sun 
warms, enlivens, and animates the earth. In the labora- 
tory of the leaf he produces the most wonderful chemical 
changes. We see his handiwork in the building of the 
forest, the carpeting of the meadow, and the tinting of 
the rose. On the ladder of the sunbeam water climbs to 
the sky, and falls again as rain. The very thunder of 
Niagara is but the sudden unbending of the spring that 
was first coiled by the sun in the evaporation from the 
ocean. Up to the sun, then, we trace all the hidden 
manifestations of power. Yet the force that produces 
such intricate and wide-extended changes is only one 
twenty-three hundred millionth part of the tide that 
flows in every direction from this great central orb. But 
what is our sun itself save a twinkling star beside great 
suns like Sirius, and Eegulus, and Procyon, whose bril- 
liancy in the far-off regions of space drowns our little sun 
as the dazzling light of day does the smouldering blaze 
of some wandering hunter ? 

C?ia?iges of * Matte?*. — Chemical changes are taking 
place wherever we look — on land or sea. The hard 
granite crumbles and moulders into dust. The stout 
oak draws in the air and solidifies it ; takes up the earth 
and vitalizes it ; changes all into its own structure, and 
proudly stands monarch of the forest. But in time its 
leaves turn yellow and sere ; its branches crumble ; itself 
totters, falls, and disappears. Our bodies seem to us com- 
paratively stable, but, with the rock and the oak, they 
too pass away. All Nature is a torrent of ceaseless 



CONCLUSION. £39 

change. We are but parts of a grand system, and the 
elements we use are not our own. The water we drink 
and the food we eat to-day may have been used a thous- 
and times before, and that by the vilest beggar or the 
lowest earth-worm. In Nature all is common, and no use 
is base. Those particles of matter we so fondly call our 
own, and decorate so carefully, a few months since may 
have dragged boats on the canal, or waved in the meadow 
as grass or corn.* From us they will pass on their cease- 
less round to develop other forms of vegetation and life, 
whereby the same atom may freeze on arctic snows, bleach 
on torrid plains, be beauty in the poet's brain, strength 
in the blacksmith's arm, or beef on the butcher's block. 
Hamlet must have been somewhat more of a chemist than 
a madman when he gravely assured the king that " man 



* The % truth that matter passes from the animal back to the vegetable, and 
from the vegetable to the animal kingdom again, received, not long since, a curi- 
ous illustration. For the purpose of erecting a suitable monument in memory 
of Roger Williams, the founder of Rhode Island, his private burying-groundwas 
searched for the graves of himself and wife. It was found that everything had 
passed into oblivion. The shape of the coffins could only be traced by a black 
line of carbonaceous matter. The rusted hinges and nails, and a round wooden 
knot, alone remained in one grave ; while a single lock of braided hair was 
found in the other. Near the graves stood an apple-tree. This had sent down 
two main roots into the very presence of the coffined dead. The larger root, 
pushing its way to the precise spot occupied by the skull of Roger Williams, had 
made a turn as if passing around it, and followed the direction of the backbone 
to the hips. Here it divided into two branches, sending one along each leg to 
the heel, when both turned upward to the toes. One of these roots formed a 
slight crook at the knee, which made the whole bear a striking resemblance to 
the human form. (These roots are now deposited in the museum of Brown 
University.) There were the graves, but their occupants had disappeared ; the 
bones even had vanished. There stood the thief— the guilty apple-tree— caught 
in the very act of robbery. The spoliation was complete. The organic matter— 
the flesh, the bones, of Roger Williams— had passed into an apple-tree. The ele- 
ments had been absorbed by the roots, transmuted into woody fibre, which could 
now be burned as fuel, or carved into ornaments ; had bloomed into fragrant 
blossoms, which had delighted the eye of passers-by, and scattered the sweetest 
perfume of spring ; more than that— had been converted into luscious fruit, which, 
from year to year, had been gathered and eaten. How pertinent, then, is the 
question, " Who ate Roger Williams ?" 



2Ifi CONCLUSION. 

may fish with the worm that hath eat of a king, and eat 
of the fish that hath fed of the worm." •' 

Shakespeare expresses the same chemical thought when 
he says : 

* Imperious Caesar, dead and turned to clay, 
Might stop a hole to keep the wind away. 
Oh ! that the earth which kept the world in awe 
Should patch a wall to expel the winter's flaw i" 

Or, again, when he makes Ariel sing ; 

" Full fathom five thy father lies : 
Of his bones are coral made ; 
Those are pearls that were his eyes ; 
Nothing of him that doth fade 
But doth suffer a sea change 
Into something rich and strange." 

Zsife a?id *Death are thus throughout nature com- 
mensurate with and companions of each other. Oxygen 
is the destroyer, and the sunbeam the builder. Oxygen 
tears down every living structure, and would bring all 
things to rest in ashes. The sunbeam re-invigorates, 
rebuilds, and rescues from the grasp of decay. Though 
they seem to be antagonists, oxygen and the sunbeam 
really work in harmony, and each supplements the labor 
of the other. Death alone makes life possible. 



Thus we have traced some of the wonderful processes 
by which this world has been arranged to supply the 
varied wants of man. Wherever we have turned, we have 
found proofs of a Divine care planning, conforming, and 
directing to one universal end, while from the commonest 
things and by the simplest means the grandest results 
have been attained. Thus does Nature attest the sublime 
truth of Eeyelation, that in all, and through all, and over 
all, the Lord God omnipotent reigneth. 



IV. 



A p p e n 6 t x 



NAMES OF CHEMICALS 



ACCORDING TO 



THE OLD AND THE NEW NOMENCLATURE 



The New. The Old. 

i. Ammonium carbonate Carbonate of ammonia. 

2. " chloride Chloride of ammonium. 

3. " sulphate Sulphate of ammonia. 

4. Antimony sulphide Sulphide (sulphuret) of antimony. 

5. Barium sulpha f e Sulphate of baryta, or Barytes 

6. Calcium carbonate Carbonate of lime. 

7. " chloride Chloride of calcium. 

8. " hypochlorite Hypochlorite of lime. 

9. " oxide Lime. 

10. " phosphate Phosphate of lime. 

11. " sulphate Sulphate " 

12. " sulphite Sulphite " 

13. Carbon disulphide Bisulphide (bisulphuret) of carbon. 

14. Carbonic anhydride* Carbonic acid. 

15. Copper nitrate Nitrate of copper. 

16. " oxide Oxide " 

17. " sulphate Sulphate " 

18. Ferric oxide Sesquioxide of iron. 

19. " hydrate ... Hydrated sesquioxide of iron. 

20. Ferric disulphide Bisulphide (bisulphuret) of iron. 

21. Ferrous sulphide Sulphide (sulphuret) of iron. 

22. Hydrogen potassium carbonate .... Bicarbonate of potash (potassa). 

23. " protoxide (water, H 2 O).. Protoxide of hydrogen (HO). 

24. " sodium carbonate Bicarbonate of soda. 

25. " sulphide Sulphide of hydrogen. 

26. Hyponitric anhydride (acid) Nitrous acid. 

27. Iron disulphide Bisulphide (bisulphuret) of iron. 

28. " sulphide Sulphide (sulphuret) of iron. 

29. " sulphate Sulphate of iron, or Protosulphate of iron 

30. Lead acetate Acetate of lead. 

31. " carbonate Carbonate of lead. 

32. " oxide Oxide of lead. 

* See note, p. 29. In the old nomenclature it is customary to apply the term 
acid indifferently to the hydride (hydrous) or anhydride (anhydrous). 



£Jf4 NAMES OF CHEMICALS. 

The New. The Old. 

33. Lead silicate Silicate of lead. 

34. " sulphide Sulphide (sulphuret) of lead. 

35. Magnesium oxide Magnesia. 

36. carbonate Carbonate of magnesia, or Magnesia. 

37. " sulphate Sulphate of magnesia. 

38. Manganese dioxide Binoxide of manganese. 

39. Mercuric chloride Chloride of mercury. 

40. Mercurous chloride Subchloride of mercury. 

41. Mercuric oxide Red oxide of mercury. 

42. Mercury sulphide . . .Sulphide (sulphuref) of mercury. 

43. Nitric anhydride Anhydrous nitric acid. 

44. Potassium bromide Bromide of potassium. 

45. " carbonate Carbonate of potash. 

46. " chlorate Chlorate of potash. 

47. " chloride Chloride of potassium. 

48. " cyanide Cyanide of potassium. 

49. " ferricyanide Ferricyanide of potash. 

50. * l ferrocyanide Ferrocyanide of potash. 

51. " hydrate Hydrated potash (potassa), or Potash. 

52. " iodide Iodide of potassium. 

53. " nitrate Nitrate of potash. 

54. " permanganate Permanganate of potash. 

55. " sulphate Sulphate of potash. 

56. Silicic anhydride Anhydrous silicic acid. 

57. Silver chloride Chloride of silver. 

58. " cyanide Cyanide of silver. 

59. " iodide Iodide of silver. 

60. " nitrate Nitrate of silver. 

61. " sulphate Sulphate of silver. 

62. Sodium biborate Biborate of soda. 

63. " carbonate Carbonate of soda. 

64. " chloride Chloride of sodium. 

65. " hyposulphite . . . Hyposulphite of soda. 

66. " nitrate Nitrate of soda. 

67. " phosphate Phosphate of soda. 

68. " silicate . . Silicate of soda. 

69. " sulphate Sulphate of soda. 

70. Sulphuric anhydride Anhydrous sulphuric acid, or Sulphuric 

acid. 

71. " acid Hydrated sulphuric acid, or Sulphuric 

acid. 

72. Sulphurous anlrydride Anhydrous sulphurous acid. 

73. Tin oxide Oxide of tin. 

74. Zinc oxide Oxide of zinc. 

75. " Sulphate Sulphate of zinc. 



Directions for Experiments. 



The following simple suggestions will enable any student to perform all the 
experiments mentioned in this work. Many easy illustrations are also given in 
addition to those named in the text. Carefully compare them with those con- 
tained in the body 7 of the book. The Italic figures refer to the pages of the book, 
and the small ones to the number of the experiment. 

IS. — i. Put into the mortar as much potassium chlorate as will lie upon the 
point of a knife-blade, and half as much sulphur. Cover the mortar with a sheet 
of writing paper, having a hole cut in it just large enough for the handle of the 
pestle to pass through. When the two substances have become thoroughly 
mixed, grind heavily with the pestle, when rapid detonations will ensue. The 
paper will prevent loose particles from flying into the eyes. The same precau- 
tion should always be observed when pulverizing potassium chlorate. A better 
way is to purchase that salt in powder, or to make a hot saturated solution and 
pour it out in thin films on panes of glass or old plates. It then forms very 
small crystals, which can be scraped off and dried for use. After using, clean out 
the mortar carefully for other experiments. The powder can be wrapped with 
paper into a hard pellet and exploded on an anvil by a sharp blow from a ham- 
mer. Sometimes small bits of phosphorus are used instead of sulphur. Great 
care is then necessary, as the particles of burning phosphorus are apt to fly to 
some distance. 

2. Dissolve 40 grs. of common soda in one wine-glass of water, and 35 grs. of 
tartaric acid in another. On being poured together in a goblet they will violently 
effervesce. Use a glass which is large enough to prevent any of the liquid from 
running over. Neatness in experiments is essential to perfection and often to 
success. At the close of this illustration, evaporate the solution,* and a neutral 
salt will result (page 211). 

22-3.— 1. A few drops of vinegar, or any acid, will turn the purple cabbage- 
solution to a bright red ; and a little of the potash solution, to a deep green. Add 
alcohol to the red solution to keep it from freezing, and bottle for use. Dissolve 

* Pour a part of the liquid into an evaporating dish, and place this on the 
tripod over the flame of the spirit-lamp.or upon a hot stove. Heat until a drop 
of the liquid taken out on the end of a glass rod and put on a bit of glass will 
crystallize as soon as it cools. Then set the dish aside to cool, when crystals will 
soon begin to form. — In this connection it is well to remark that a cook-stove will 
be found of great use in chemical experiments, and indeed may, in the labora- 
tory, take the place of a furnace . The oven will dry apparatus and chemicals ; 
the heat is sufficient for evaporating solutions, distilling water, etc., while an 
excellent sand or water bath may be readily contrived, 



2Jf6 DIRECTIONS FOR EXPERIMENTS, 

20 or 30 grs. of litmus in an oz. of water ; filter and bottle. Dissolve also a stick 
of potash in 4 oz. of water ; filter and bottle. Fill two test-tubes nearly full of 
water ; color one with the cabbage solution and the other with the litmus solu- 
tion. To each add alternately a few drops of the potash solution and of oil of 
vitriol. The color can be changed at pleasure. 

A pipette — a glass-tube with a bulb in the middle and one end drawn to a 
point — will be found convenient for dropping liquids. In lieu of this, take a piece 
of glass-tubing,* and heating the end in the flame of the spirit-lamp (the greatest 
heat is near the tip), seal the openings. This tube will readily take up a drop 
upon its extremity, and will be found useful for stirring liquids. 

27. — 1. Put into a dry test-tube 24I grains of pure potassium chlorate and heat 
cautiously. The test-tube may be supported b} r a strip of thick paper twisted 
around it at the top. Move the tube to and fro through the flame at first, until 
it becomes fully heated ; keep the tube inclined and not perpendicular, letting the 
flame strike the side rather than the bottom. Hold the thumb lightly over the 
mouth of the tube. The salt melts quietly and the tube will soon be filled with 
O, as proved by its re-igniting a glowing splint introduced into it. When no 
more gas is evolved, allow the salt to cool, shaking it gently to prevent its attach- 
ing itself to the tube. When cold the residue will weigh 14.9 grains. The 
residue is no longer a chlorate, and it gives out no yellow gas if moistened with 
H 2 S0 4 , but will yield a white precipitate with AgN0 3 , which shows it to be a 
chloride. Most of the following experiments may be performed in test-tubes as 
above, but when it is desirable to make a larger quantity of O, one ounce of 
potassium chlorate is very carefully pulverized and mixed with half that quan- 
tity of black oxide of manganese, which has just been strongly heated on an 
iron plate or sand-bath, and allowed to cool.t Be careful not to grind them 
together. The mixing is effected by placing them both on sheets of clean paper 
and pouring them back and forth from one sheet to the other until the mixture 
has a uniform gray color. Place the mixture in a flask ; fit a cork to the nozzle ; 
then withdraw the cork, and with a round file bore a hole through it just large 
enough % to admit a glass tube bent § as shown in Figs. 2 or 10. Return the cork 

* The tube may be cut of any length. Lay it upon the table, and with a 
three-cornered file make a deep scratch where you wish to break it ; then hold 
the tube in both hands, placing a thumb on each side of the scratch, and with a 
steady pressure the glass will break at the desired point. Two tubes, each closed 
at one end, may also be easily obtained by heating a piece of tubing in the 
flame until a ring of the glass becomes very soft, when, by pulling upon the 
opposite ends of the tube, the heated portion will be drawn out, diminished in 
size, and the opening closed. A little practice will enable the student to do this 
neatly and expertly. Gas-jets may also be made in this way for the experiments 
illustrated in Figs. 12, 15, 16, and 19. 

t In order to test the purity of the materials, and thus avoid any danger of an 
explosion, it is well, previous to putting the mixture in the flask, to^ place a little 
in an iron spoon and heat it over the lamp. If the gas pass off quietly, no dan- 
ger need be apprehended. 

% Whenever corks leak gas they mav be wrapped with thin strips of wet 
paper to make them fit more tightly ; or the entire nozzle may be smeared with 
tallow, or covered with sealing-wax, if heat is not used. In that case use a 
poultice of linseed meal, or a little plaster-of-Paris may be wet and applied. 

§ A glass tube may be bent at any point by softening that part in the flame of 
the spirit-lamp. Practice alone will give the required expertness. The follow- 
ing points should be observed: 1. Keep the tube constantly turning between 
the fingers so that it may be equally. heated on all sides ; 2. Do not twist or pull 



DIRECTIONS FOR EXPERIMENTS. 21ft 

and tube, arrange the apparatus as shown in either of the figures, and apply the 
heat. This inust be done very cautiously at first, holding the lamp in the hand 
and moving it around so that the flame may strike all the lower part of the flask, 
and thus expand it uniformly. Be careful also that no draft of cold air strikes 
against the heated glass. The first few bubbles of gas will consist mainly of the 
air contained in the flask, and should not be caught. When the gas begins to 
pass over freely, diminish the heat.* When the gas ceases, remove the stopfer 
from the flask, or lift the end of the tube out of the water ; otherwise, as the 
flask cools, and a vacuum is formed, the water in the tub will rush back into the 
flask and break it. When the retort is nearly cool, pour in some warm water 
to dissolve the residuum, which may then be poured out and the flask dried for 
future use. 

Instead of bending the glass tubing it may be cut into short lengths and the 
pieces joined by bits of rubber tubing, as in Figs. 10 and 13. The advantage of 
this is that the flexible joints are not liable to break, and the apparatus may be 
more easily moved. Where a large quantity of O is to be made, a copper retort 
and rubber tubing will be found cheap and convenient. No especial care is then 
needed in managing the heat.t — In place of the pneumatic tub, a pail or a tin pan 
may be used, letting the bottle rest on a shelf as in Fig. 10, or on a couple of 
bricks. — The bottles for collecting the gas may be the regular " deflagrating jar " 
of the chemist, or the common " packing bottle" of the druggist. They are to 
be sunk in the water of the pneumatic tub and filled ; then inverted and lifted 
upon the shelf, carefully keeping the lower edge of the bottle under the water. 
The bottles may also be filled from a pitcher, then closed with the hand or a 
plate, and quickly inverted and placed on the shelf in the tub or pan ready for 
use. As soon as a bottle is filled with gas a plate may be slipped under the 
mouth, and thus, leaving enough water in the plate to cover the lower edge, be 
set aside as in Fig. 2. Gas may be passed from one jar to another in the manner 
shown in Fig. 17.— While the gas is being collected, the water from the bottles 
which are filling may cause the tub to overrun ; to prevent this, arrange a siphon 
to carry off the water into a pail below the table. — When a jar of gas is wanted 
for use, remove it to the tub, slip a plate under the mouth, or simply close it with 
the hand, and lifting the jar out, carry it to the table and place it mouth upward. 
Uncover only when the experiment is ready to be performed, as the gas will 
slowly diffuse. 

29—31. — 1. The experiment with the candle may be very strikingly performed 
by filling a common fruit-jar with O, and another with N. The covers may be 
loosely laid on top, and the lighted candle passed quickly from one to the other, 
as mentioned in note on page 43. The candle may be simply stuck on the end 
of a bent wire, as in Fig. 14, but it is much neater to have the tinsmith fit a little 
cup for its reception, as shown in the figure. 

the tube while heating ; 3. Do not bend it until very soft ; if not hot enough the 
eibow will be flattened. Blowing gently into the tube at the moment of bending 
also prevents flattening. 

* The gas often looks cloudv, owing to little particles of the salt which are 
carried over suspended in it in fine powder ; but these gradually become dissolved 
in the water. 

t If, during the operation, the gas suddenly ceases to come off, remove the 
flame and ascertain whether the delivery tube is not choked up, which would 
result in a very violent explosion of the retort. 



2JfS DIRECTIONS FOR EXPERIMENTS. 

2. Worn-out watch-springs can be obtained gratis of any jeweller, and may 
be easily straightened by slightly heating and then drawing them between the 
fingers. If the end of each spring be strongly heated and then pounded with a 
hammer on any smooth, hard surface, the temper may be drawn and the edge 
sharpened. Make a slit with a knife in the side of a match, into which insert the 
edge of the spring. Take a piece of zinc or tin large enough to cover the mouth 
of the jar containing the O, and make a hole through it with a nail. Pass the 
other end of the spring through this hole, and then through a thin cork. The 
spring is now ready for burning. The metal cover will prevent the flame from 
coming out of the jar and burning one's hand, and the cork will hold the spring 
in its place.* When the match is ignited, and then lowered into the jar of O, the 
spring should not reach more than half-way to the bottom, and should be pushed 
down as it burns. A cheap packing-bottle should be used, as the glass is fre- 
quently broken by the melted globules of iron. Do not fill it quite full of gas, as 
then, on inverting, a little water will be left at the bottom, or some fine sand may 
be thrown into the jar before the experiment. The illustration may be repeated, 
with a coil of fine iron wire. The springs from an old hoop-skirt burn nicely 
in O. 

3. If brimstone be used in the experiment with S, and it fails to light readily, 
pour upon it a few drops of alcohol, and then ignite. 

4. When S, P, charcoal, a wax candle, Na, and other substances are to be 
burned in O, they may be supported on the end of pieces of glass tube bent like 
the letter J, and left open at the shorter end only. For this purpose, covers 
must be provided with holes large enough for the glass tube to pass through. Or 
a "deflagrating spoon " may be readily extemporized to contain the phosphorus. 
Hollow a small piece of chalk and attach a wire to it, which may then be secured 
to a metal top, as in the case of the watch-spring. This need not be pushed down 
into the jar as the burning progresses. Be careful to cut the phosphorus under 
water, to dry it carefully with blotting-paper, and not to handle it. The fumes 
are very disagreeable, and should not be inhaled or allowed to escape into the 
room. They soon dissolve when shaken with a little water, which then gives an 
acid reaction, H 3 P0 4 . 

5. The experiment of burning P under water may be easily shown by throw- 
ing a piece of P into a glass of hot water. It melts and looks like a thick oil under 
the water. A fine stream of O gas may then be passed through a glass tube 
down to the P, which burns brightly under water. (Note, p. 130.) 

6. The oxidation of one solid by means of nascent O liberated from another 
solid can be shown as follows : Heat about 5 grams of potassium nitrate (salt- 
petre) in a test-tube until it melts quietly. Remove the lamp and throw in pieces 
of S as large as peas, when they burn with an intensely bright flame. The heat 
is often sufficient to melt the glass, and the precaution should be taken to hold it 
over an iron plate or sand-bath. Or melt a quarter of a pound of saltpetre in an 
evaporating dish ; an ordinary tin cup will answer. Put it on some burning 
coals in a draught to carry off the fumes. Plunge into the liquid a piece of bark- 

* It is well to obtain several pieces of thin board or shingles, about 6 inches 
square, bore a small hole in the center and insert a match end or small plug. 
These may be used as covers in most experiments where a deflagrating spoon is 
to be employed. The handle of the spoon is passed through this hole and held 
in place by the small plug. 



DIRECTIONS FOR EXPERIMENTS. 2Jf9 

charcoal strongly ignited. The oxygen of the saltpetre will support the combus- 
tion, and the charcoal will deflagrate in a rushing volcano of scintillations. 

7. In burning bark-charcoal in O, force the gas into the bottle through a bit of 
rubber-tubing at the mouth. By placing this at one side, the gas is given a rotary 
motion, and the sparks of ignited charcoal will drive around the bottle in a beau- 
tiful maelstrom of fire. The gas may be forced in from a rubber bag, and this 
striking effect easily produced. 

8. Arrange a receiver upon the bed-plate of the air-pump so that O may be 
admitted from a gas-bag by turning a stop-cock. Put under the receiver an 
ignited tallow candle with a big wick. Exhaust the air until the flame goes out 
and there is left only a coal of fire. Admit the air, and it will have no effect to 
restore the blaze. Force in some O quickly, and the coal will burst instantly into 
a brilliant white light, brighter than at the first. 

9. Burn a small piece of Na or K in a jar of O, and dissolve the white powder 
formed. The solution restores reddened litmus, showing it to be an alkali. 

89. — 1. Put in an evaporating dish a little starch ; cover it with water in which 
a few crystals of potassium iodide have been dissolved, and heat. Stir the liquid, 
to prevent lumps. When cooked, immerse in the paste slips of white blotting or 
clean writing-paper, and hang them up to dry. They must be moistened when 
used. Be careful not to heat the glass tube too hot, lest the ether-vapor may 
ignite. Keep the jar well filled with vapor by frequently shaking it. Lower into 
the ozone a bit of silver-leaf moistened with water ; it will quickly crumble into 
the oxide. 

2. Ozone may also be prepared by the slow oxidation of phosphorus in the 
following manner : Scrape off the white coating of a stick of phosphorus under 
water, and cut the cleansed phosphorus into pieces 12 or 15 millim. long.* Place 
one of these pieces in a wide-mouth litre-bottle full of air, with about a tea- 
spoonful of water at the bottom. Close the mouth of the bottle with a glass plate, 
and expose the whole for an hour or two to a temperature of 15 or 20 C. Then 
invert the neck of the bottle in water, and allow the phosphorus to fall out. Re- 
place the glass plate, and withdraw the bottle and its contents from the water. 
The phosphorus in this experiment undergoes a slow oxidation, during which a 
little ozone is formed, and is left mixed with the air ; but the ozone will be again 
destroyed if it is left too long with the phosphorus. 

3. Add to the bottle of air which has been ozonized by means of phosphorus, 
a few drops of a very dilute blue solution, formed by dissolving powdered indigo 
in strong sulphuric acid, and then diluting it with water. If the blue liquid be 
shaken up with the ozonized air, the color will quickly disappear. 

4. In making ozone in the ordinary way, with a hot glass rod stirred in ether- 
vapor, when there is water at the bottom of the jar, some peroxide of hydrogen 
will be made and absorbed by the liquid. When ozone is present, on adding to 
the liquid the iodide-of-potassium-starch solution, the characteristic blue of iodine 
is developed. In the absence of ozone, no such change will take place. But on 
adding to the liquid a tiny drop of the transparent solution of the sulphate of iron, 
the iodine will at once be set free and the characteristic blue be produced. 

* The metric system is used in a few of the examples which follow, in order to 
accustom the pupil to the mode which is adopted by all scientific men in their 
investigations and treatises. Any arithmetic will explain the meaning of the 
terms, if they are not already familiar to the scholar. 



250 DIRECTIONS FOR EXP ERIME NTS. 

5. Let some ozone pass into a clean bottle containing a little pure mercury. 
Shake the whole very carefully. The metal will change so as to act like an amal- 
gam of tin and mercury, and will form a mirror on the sides of the bottle. 

6. Peroxide of hydrogen may be readily made by allowing water to drop very 
slowly through a tube containing bits of amalgamated zinc. The liquid may be 
tested for the peroxide by the iodide-of-potassium-starch solution in the presence 
of ozone, as before. 

Ul.—i. The phosphorus will, without the aid of heat, gradually remove the O 
from the air, forming phosphorus anhydride (P. 2 3 ), which will be dissolved by 
the water, and in a day or two the gas which is left will be nearly pure N. 

2. To show the proportion of O and of N in common air. Take a long glass 
tube ; with a camel's-hair brush and black paint mark upon the outside the divi- 
sion into fifths ; seal one end air-tight and fit a cork to the other. Place a bit of 
phosphorus in the tube near the open end and insert the cork. Heat slightly over 
a spirit-lamp to ignite the phosphorus, and then elevate the stoppered end so as 
to let the burning and melted phosphorus run slowly to the other end of the tube, 
combining with the O of the air as it goes. Now let the tube cool a moment, 
and then remove the cork underneath the surface of water, which will instantly 
rise and fill one-fifth of the tube. Replace the cork, and then the tube may be 
lifted out and shown to the class, all of whom will see that one-fifth of the air has 
been removed and its place occupied with H 2 0, while the remaining four-fifths 
still appears. 

U2. To make the iodide of nitrogen, cover a few scales of iodine with strong 
aqua-ammonia. After standing for a half-hour, pour off the liquid and place the 
browm sediment in small portions on bits of broken earthenware to dry. They 
may then be carried very carefully to the class-room and exploded by a slight 
touch of a rod or even a feather. It can also be made by pouring aqua-ammonia 
upon chloride of iodine. 

l+k. — 1. For making HNCL, a flask may be used, and the heat of the spirit-lamp 
will be sufficient. Take equal weights of sodium nitrate and strong sulphuric 
acid. Nitrate of potash will answer in place of the sodium salt. A free circula- 
tion of air is necessary. The fumes may be caught in an evolution-flask, which 
is kept cool by a towel frequently wet. When the retort is partialry cooled, at 
the conclusion of the process, pour in a little warm water, to dissolve the potas- 
sium sulphate, otherwise the retort may break by the crystallization of the salt. 

h6. — 1. A special apparatus is necessary both for preparing and inhaling nitrous 
oxide safely. This consists of a glass retort — as shown in the cut — a wash-bottle, 
and in addition a gas-bag of from twenty to fifty gallons capacity for storing the 
gas, and a smaller bag of from three to five gallons, with a wide, wooden mouth- 
piece for inhalation. It is well to pass the gas through a large w 7 ash-bottle half- 
full of iron sulphate solution and a second half-full of H 2 0, as shown in Fig. 13, 
thence by a rubber tube directly into the large gas-bag. The utmost care should 
be taken both in preparing and administering this gas, as other oxides of nitrogen 
are liable to be present, especially if too high a heat is used. Before preparing 
the gas, pour into the bag a couple of gallons of H 2 0, by standing over which it 
will be purified in a few hours. When about to administer the gas, let the subject 
grasp his nose firmly between his thumb and forefinger ; then, inserting the 
w 7 ooden mouth-piece, be careful that he does not inhale any of the external air, 
but takes full, deep breaths in and out of the gas-bag. Watch the eye of the 
subject, and notice the influence of the gas. Great care is necessary, and no one 



DIRECTIONS FOR EXPERIMENTS. 251 

should ever inhale the gas who is not in good health, who is troubled with a rush 
of blood to the head, any lung or heart disease, or is of a plethoric habit. N 2 
should never be administered except when prepared and given by an experienced 
person. 

2. Fill a small jar with the gas, and thrust into it a splinter of wood the end of 
which is glowing brightly ; it will burst into flame. 

3. Place some S in a deflagrating-spoon ; kindle, and when burning briskly 
lower into the gas ; it will burn with a pale rose-colored flame. . 

4. Half-fill a test-tube with gas, over water. Close the tube under water 
firmly with the thumb, and then agitate the water and gas together. On remov- 
ing the thumb under water, a considerable rush of water into the tube will occur, 
as the gas is soluble in about its own volume of cold water. By this circumstance 
the gas is easily distinguished from O. 

5. To show the effect of HN0 3 upon the metals, procure bits of tin and copper 
from the tinsmith. Take six wine-glasses and place them in a row upon ordinary 
soup-plates containing a little water. Cover each with a beaker-glass or bell-jar. 
In one put a strip of copper, in another a piece of silver, in another a piece of pure 
tin (not tinned iron), in another a strip of zinc, in another a new iron nail, in the 
last a bit of platinum wire or foil. Pour strong nitric acid upon each, and cover 
immediately. The copper, silver, and zinc dissolve, the latter with a violent 
evolution of gas. The tin is oxidized to a white powder, while the iron and plati- 
num are unaffected. Touch the iron with a piece of copper wire, and it begins 
to dissolve. Put another new nail in dilute nitric acid, and it is rapidly dissolved. 

6. Mix slowly together 1 oz. oil of vitriol and 2 oz. of the strongest nitric acid. 
When cold, dip paper into the mixture, and quickly wash with cold water and 
dry. The paper will burn with a flash like gunpowder. To avoid getting the acid 
on the hands, use glass tubes or rods for taking the paper out of the acid. Cotton 
treated in the same way becomes soluble in a mixture of alcohol and ether, and 
is used by photographers in making collodion. (Page 189.) 

U7. — 1. When a jar is filled with the NO, it may be lifted out of the H 2 and 
inverted, when the N0 2 will pass off in blood-red clouds. If the jar be left in the 
cistern and one edge be lifted so as to admit a bubble of air, red fumes will fill the 
jar. By standing a moment, the water will absorb the red vapor. The process 
may be repeated several times with the remaining gas. The variation of this 
experiment described in the note on page 47 will be found very interesting. The 
change of color produced by mixing nitric oxide with any gas containing free O, 
often affords a convenient means of detecting small quantities of O when present 
in admixture with other gases, such, for instance, as coal-gas. Hence NO may be 
used to distinguish between O and N 2 0. 

2. Into a large jar inverted over water, introduce a measured quantity of NO 
and exactly half as much pure O. The two combine to form N0 2 , which is soon 
dissolved in the water and disappears. This illustrates Gay Lussac's law that 
gases combine in simple proportions by volume. If we take 4 parts of NO to 
1 part of O, we have N 2 O a , also a red gas.* 

* It is very dangerous to breathe the red fumes (generally a mixture of N0 3 
and N 2 3 ) given off by the action of nitric acid upon the metals, starch, and other 
oxidizable bodies. The nitrous fumes produced when nitric acid is poured upon 
starch or sugar are passed into alcohol and sold under the name of sweet spirits 
of nitre. Oxalic acid (see p. 210) remains in the retort. 



252 DIRECTIONS FOR EXPERIMENTS. 

U8. — Carefully compare the three following experiments : 

i. Mix intimately 3 grams of fine iron filings in a mortar with 0.2 gram <?r 
caustic potash ; introduce the mixture into a test-tube, to the mouth of which a 
cork and a bent tube are attached. Heat the mixture over the spirit-lamp ; gas 
will escape, and may be collected over water in a. test-tube. It burns with flame, 
and consists of H. At a high temperature, the Fe displaces H from the caustic 
potash: Fe + 2 KH0 = FeO+K 2 + H 2 . 

2. Mix 3 grams of iron filings intimately with 0.2 gram of nitre. Heat the 
mixture and collect the gas as before ; it will not burn, does not render lime- 
water milky, and is, in fact, N. The Fe has combined with the O of the nitre, 
forming potash and liberating N: 5Fe + 2KN0 3 =5FeO + K a O+ N 2 . 

3. Mix 6 grams of iron filings with 0.2 gram of caustic potash and 0.2 gram of 
nitre, and heat the mixture in a tube. The gas which now comes off has the 
pungent smell of hartshorn ; it is strongly alkaline, and immediately restores the 
blue color of reddened litmus. In the reaction which takes place, the H and the 
N, at the moment that each is set free, combine, and form H 3 N. 

4. Place a little solution of litmus, feebly reddened by the addition of a drop 
or two of acid, in a basin ; carefully raise the flask full of ammonia gas from the 
gas-delivering tube ; close the flask with the thumb, plunge the mouth under 
the solution of litmus, and withdraw the thumb ; the liquid will rush rapidly 
into the flask, the ammonia gas will be absorbed, and the red liquid will 
become blue. 

5. Boil a fluid-oz. of NH 4 H0 in a flask provided with a cork and tube, as shown 
in Fig. 12 ; the gas will come off freely. Apply a light to the jet ; it will not 
burn readily, but a pale greenish flame will play over the top of the light. Place 
in a bottle of O the tube from which the gas is escaping, and then apply a light ; 
it will now burn with a green flame. 

6. u Vortex rings " formed by the fumes of chloride of ammonium. A com- 
mon wooden box about three feet square has a circular hole six inches in diame- 
ter cut in its front face, while the back of the box is removed and its place 
supplied by a piece of tightly-stretched canvas or linen cloth. Let the vapors of 
ammonia and hydrochloric acid pass constantly into the box through small holes 
at the side. When the box is filled with the white fumes of the chloride of 
ammonium, a sharp but gentle tap on the canvas back will drive out, through the 
hole in front, a beautiful ring of smoke that will traverse a large room and will 
have force enough to extinguish a lighted candle. 

50.— 1. For preparing H the apparatus shown in Fig. 13 is very convenient. 
The wash-bottle, d, is necessary only when it is desired to purify the gas for 
inhaling. A common junk-bottle, fitted with a cork and a glass tube, will 
answer for all ordinary experiments, but a u hydrogen generator," as described 
below, is much more satisfactory. The Zn for making H should be granulated.* 
Water may be poured into the flask until the lower end of the funnel is covered, 
before adding the acid. The flow of gas may be regulated by additions of acid, 
as may be wanted. One part of acid to 10 or 12 parts of water will liberate the 
gas rapidly. If too much H a S0 4 be added the liquid is apt to froth over. 

A constant hydrogen generator can be readily made by taking two bottles with 
tubulature near the bottom, such as are sold by druggists for the " nasal douche," 

* This is easily done by melting the Zn in an iron ladle, and pouring the 
metal slowly from a little height into a basin of water. 



DIRECTIONS FOR EXPERIMENTS. 



258 





ZINC 




and connecting them with a 
strong rubber tube. One is 
fitted with a cork and deliv- 
ery tube provided with a 
stop-cock. In this bottle is 
placed a layer of pebbles or 
broken glass, and upon this 
a quantity of zinc scraps. 
In the other bottle is dilute 
H u S0 4 . On opening the 
stop-cock the acid comes in 
contact with the zinc and H 
is evolved. As soon as the 
stop-cock is closed, the pres- 
sure of the gas drives the 
acid back into the other bot- 
tle. The same kind of ap- 
paratus may be employed 
for generating CO a or H a S. 

A hydrogen generator, similar in principle to the D5bereiner's lamp (Fig. 18), 
can be made by cutting off the bottom of a tall and narrow bottle, filling it with 
zinc scraps and closing at the lower end with a perforated rubber cork, and at the 
upper end with a perforated cork carrying a brass or glass tube and stop-cock. 
Place it upright in a jar of dilute sulphuric acid. 

In experimenting with H, great care must be used not to ignite the jet of gas 
until all the common air has passed out of the flask ; otherwise a severe explo- 
sion will ensue.* It is a safe precaution to test the gas by passing it in bubbles 
up through H 2 0, and igniting them at the surface ; the force of the combustion 
will indicate if there be any danger. H must not be kept in bags for any great 
length of time, as the air will gradually force itself in, and the gas will partly 
pass out by the law of diffusion, thus forming a mixture which it is dangerous to 
ignite. 

2. The gases may be mixed in the following manner: Fit a good cork into 
the neck of a large jar, and pass through it a tube 5 centim. long. Bind a short 
piece of rubber tubing firmly to the tube, and close this elastic tube with a small 
screw-vise. t Fill the jar with water over the pneumatic tub. Fill a small jar 
which will hold about half a litre with O, and transfer it, as shown in Fig. 17. to 
the large jar. Fill the same jar with H, and transfer it to the large jar. Repeat 
the operation with the H, so as to obtain in the larger jar a mixture of half a litre 
of O and 1 litre of H. Having previously softened a thin bladder by soaking it in 
water, tie into the neck of it a glass tube 5 centim. long ; then adjust to the pro- 
jecting portion a piece of rubber tubing provided with another nipper-tap. Press 
the air out of the bladder ; connect by means of a short piece of glass tubing the 
two pieces of rubber tube ; depress the jar in the pneumatic tub, and then open 



* Always wrap a cloth around the H generator when you ignite the gas, as 
an explosion may take place at any time. 

+ Small vises, or " nipper-taps," as they are called, are sold for this purpose. 
They are cheaper than stop-cocks, and answer every purpose. In lieu of these, 
common spring clothes-pins may be used. 



25 Jf DIRECTIONS FOR EXPERIMENTS. 

each nipper-tap. The gas will now pass into the bladder ; if it does not, press 
the jar deeper into the water ; close both nipper-taps, and remove the bladder. 
Now place the end of the tube attached to the bladder under some soap-suds, 
and force out the mixed gases by squeezing the bladder so as to make a lather. 
Careftdly remove the bladder to a distance, and then apply a light to the troth 
of soap-suds. A loud explosion will immediately follow. — A clay tobacco-pipe 
may be attached to the gas-bag by means of a bit of rubber tubing. Dip the 
pipe-bowl into the soap-suds, and lifting it out, blow a bubble with the mixed 
gases, and then detach it by a quick motion. When the gas-bag is removed, 
ignite the bubble, which will explode sharply. If bubbles be blown with H 
alone, they will rapidly rise, and if out of doors, will float to a great distance. * 

3. H is the lightest known substance. Fill two bottles with the gas, suspend 
one inverted from the ring of the retort holder and place the other right-side up 
on the table. In a few minutes the upright cylinder will be found to contain 
little or no H, while the inverted bottle is nearly full. 

4. Invert an empty beaker glass or paper box, and suspend it from the end of 
the scale beam (Fig. 26). Balance it carefully, then fill it with H gas. It will be 
found much lighter than before. 

5. Take a small porous cup, such as is used for galvanic batteries. Fit a 
cork to it and pass a long glass tube through the cork. Cover the cork with 
plaster of Paris. Place it upright with the lower end of the tube dipping into a 
colored liquid (CuSO t + NH 4 H0). Hold a jar of H over the porous cup. The H 
enters the cup, driving the air out of the lower end of the tube. Remove the jar 
and the liquid will rise several inches in the tube. (See Physics, p. 50.) 

6. A substitute for spongy platinum in the experiments with hydrogen gas. 
Make a cylinder of pumice stone % of an inch in diameter. With a fine saw cut 
it into disks about one-twentieth of an inch thick. Soak these for some time in a 
strong solution of bichloride of platinum in alcohol, and then as long in an alco- 
holic solution of sal-ammoniac. After being once thoroughly ignited these disks 
will inflame a jet of hydrogen. 

60.— 1. The analysis of water t can be readily performed as follows: Take a 
wide bottle (the height is unimportant) and cut it off about i\ inches below the 
neck, by making a scratch w T ith a three-cornered file and then applying near the 
scratch a very hot piece of wire or glass, or a small blowpipe flame. The crack 
will follow the flame slowly around the bottle. Take two strips of platinum foil, 
and put one on each side of a well-fitting cork, so that one end extends into the 
bottle, the other outside of the neck. Support the apparatus inverted upon a 
ring of the retort stand, and fill nearly full of water acidulated with H 2 S0 4 . 
Connect one strip of Pt with each pole of a galvanic battery. Bubbles of gas at 
once appear and can be collected in inverted test-tubes and tested. Instead of a 
bottle neck, a broken funnel may be employed. (See Physics, p. 237.) 

2. The synthesis of water may be shown, and also its composition by weight, 
by passing dry H over dry CuO. The CuO is placed in a bulb-tube of hard 
glass C and weighed. The chloride of calcium tube D is also weighed. The H 

* If one has a large rubber gas-bag with stop-cock and rubber tubing, and a 
glass receiver fitted with a stop-cock on top. these may be attached and the gases 
measured in the receiver and then passed directly into the bag. Such apparatus, 
though convenient, is not necessary to illustrate the properties of the gases. 

t The so-called Water Gas is made by passing H a O over red-hot coal. It is 
chiefly H + CO. 



DIRECTIONS FOR EXPERIMENTS. 



255 



generated in A is dried by CaCL at B, and passes over the CuO at C. When the 
air has all been expelled, heat the CuO until it has a bright red color. Allow the 
H to pass through until the tube C is cold. Take the apparatus apart and weigh 
the tube C; it will have decreased in weight by a quantity equal to that of the O 
expelled. Weigh the tube D. It has increased by a quantity equal to that of 
the water formed. If C has lost 16 grams in weight, D will have increased 




i3 grams in weight, showing that 16 parts of O will form 18 parts of water, by 

taking up two parts of H. 

3. Burning H in O. Attach a CaCI 2 drying tube to a hydrogen generator, and 

to this a glass tube bent twice at right angles and 

then turned up at the end, as shown in the figure. 

Take a small piece of Pt foil and roll it around a 

darning needle so as to form a small tube. Soften 

the end of the glass tube and slip this little tube 

into it while hot, then hold them in the flame until 

the glass settles down against the Pt on all sides. 

When the air has all been expelled from the gen- 
erator, throw a towel over it 
and ignite the H, then bring 
it into a broad jar of O. The 
heat is very intense, hence 
the need of a Pt tip. 

4. Burning O in H. To 
show the reverse experiment 
of burning O in H, or illumi- 
nating gas, take a large lamp 
chimney and fit a cork in 
each end. In the upper cork 
insert a glass tube drawn out 
to a jet D. In the lower end 
insert a bent glass tube A 

and a metal tube C made by rolling up a strip of sheet 
iron or brass. Fit a cork to the metal tube and pass a 
glass tube with a Pt tip on it through this cork B. Attach 
the tube A to an H generator, and when the whole appara- 





256 DIRECTIONS FOR EXPERIMENTS. 

tus is, full oi H, ignite it at D and C. Connect i? with a gasometer or bladder 
of O, then quickly insert the cork into the opening C, so as to extinguish the 
flame there. Let the O pass in slowly. The O will be seen to burn in an atmos- 
phere of H. Cut off the supply of O and extinguish all flames before removing 
the supply of H, to avoid an explosion. 

59. — i. Grind in a mortar 50 or 60 grams of sodium sulphate with about twice 
its weight of water at 15 C. The water will dissolve a considerable portion, 
but not the whole of the salt. Pour this saturated solution into a flask, and 
warm it gently ; it will now dissolve 50 grams more of the salt without difficulty. 
When all the salt is dissolved, cork the flask, place it on the table and allow it 
to cool slowly. Be careful not to shake it when cold. On removing the cork 
the whole becomes a mass of crystals, which can be seen to shoot through the 
liquid in every direction. Pour off the liquid, and dry the crystals by pressing 
them between a few folds of blotting-paper. When they appear to be dry, put 
a small quantity of the crystals into a test-tube, and apply a gentle heat ; the 
salt will liquefy, and on continuing to apply the heat a large quantity of water 
will be driven off, and a dry, white powder will be left in the tube. 

2. Take some of the fresh crystals of sodium sulphate ; let them lie exposed 
on a piece of blotting-paper for two or three days. They will gradually lose 
their water and crumble down, or effloresce into a white powder.* Dissolve 
150 parts, by weight, of hyposulphite of soda t in 15 parts boiling water, and gently 
pour it into a tall test-glass so as to half fill it, keeping the solution warm by 
placing the glass in hot water. Dissolve 100 parts, by weight, of sodium acetate 
in 15 parts hot water, and carefully pour it in the same glass ; the latter will 
form an overfying layer on the surface of the former, and will not mix with 
it. When cool there will be two supersaturated solutions. If a crystal of 
sodium hyposulphite be attached to a thread and carefully passed into the 
glass, it will traverse the acetate solution without disturbing it, but, on reach- 
ing the hyposulphite solution, will cause the latter to crystallize instantaneously 
in large rhomboidal prisms. (Compare p. 133.) 

4. Take two four-ounce bottles, and put in each a teaspoonful of white sugar. 
Fill one bottle nearly full of pure rain or distilled water, the other with impure 
water. Cork them, and let them stand a few days ; in one bottle will be seen a 
fungoid growth, resembling fuzz or lint ; the water in the other bottle remains 
clear. (Note, p. 192.) The sporules or germs that fall into the water find suitable 
nutriment for their development in one case, but not in the other. Any well or 
spring water in which this change takes place is unfit to drink. (P. 60, note.) 

5. Select a thin, porcelain dish which will hold 60 or 80 cub. cm. ; place it in 
one pan of the balance, and trim a piece of lead until, when placed in the other 
scale-pan, it will counterpoise the dish. Measure a quarter of a litre of spring- 
water, and pour some of it into the weighed dish ; place it over a very small gas- 
flame, so as to evaporate the H 2 gently, without allowing it to boil ; add the 
rest of the H 2 from time to time until it has completely evaporated. Dry the 
salts thus obtained, and weigh what is left as accurately as you can. By multi- 
plying this quantity by 4, you will obtain the amount of soluble solid substances 
per litre which that particular specimen of water contained. This is the basis of 
the plan which, with many additional precautions, is adopted for determining the 

* Common washing soda, Na 2 C0 3 + ioH 2 0, will do the same, 
t To be had of any photographer, under the name of " hypo." 



DIRECTIONS FOR EXPERIMENTS. 257 



quantity of salts in the process of analyzing waters to be used for drinking or 
manufacturing purposes. 

66.— i. Small paste-diamonds may be obtained of a jeweller, to illustrate the 
forms of cutting the diamond. 




69, — i. Place a filtering-paper in the glass funnel,* and in it two ounces of 
bone-black or finely-powdered charcoal. Filter through it water colored with 
ink, litmus, or any other impurities. In pouring the liquid into the filter, hold a 
glass rod against the edge of the pouring vessel, so as to direct the stream into 
the funnel. The funnel may be placed in the nozzle of a bottle, but must not fit 
closely. A bit of wood or a thread inserted between the stem of the funnel and 
the nozzle will leave an opening sufficient for the egress of the air. 

2. Slip a piece of freshly-burned charcoal under the edge of a long tube pre- 
viously filled with dry ammonia gas,t and standing over Hg. The charcoal will 
quickly absorb the H 3 N ; the whole of the gas, if pure, will disappear, and the Hg 
will fill the tube. 

3. Weigh a piece of freshly-burned charcoal as soon as it is cold ; leave it 
exposed to the air for twenty-four hours, and weigh it again ; it will be found to 
be heavier. Place the charcoal in a glass tube, and heat it over a lamp ; moisture 
will be driven off, and will become condensed on the cold sides of the tube. 

4. Shake up with a little powdered charcoal some stagnant water which has 
been kept till it smells offensively. In an hour it will have lost all its disagree- 
able odor. 

5. Mix in a mortar twenty grams of litharge with forty grams of NaCI and one 
gram of powdered charcoal ; cover with a little more salt, and place the mixture 
in a small, clay crucible ; heat it to bright redness in the fire. When the mixture 
is melted, take the crucible out of the fire and let it cool. When quite cold, 
break the crucible, and a bead of Pb will be found at the bottom, under the 
melted salt, the C having taken the O from the PbO. 

6. Break the head off a match, and warm the match-stick in the flame. At the 
same time hold one end of a large crystal of sal-soda in the flame until it 
melts. Rub the stick with the melted soda until it is well covered ; then hold it 
in the flame until the protected stick is completely charred. Mix a very little 
PbO with some melted soda and put on the end of the stick, and place it for a 

* In order to prepare this filter, fold a square of paper, as shown in the figure 
above, first into half, and then again into a quarter of its first size (b) ; cut off the 
edges in the direction of the dotted line shown in the left-hand figure (a), open 
out the folded paper (<:), and drop it into a funnel a little larger than the paper 
cone. \ 

t The gas may be dried by passing it through a tube filled with pieces of cal- 
cium chloride (see Fig. 16), obtained in making C0 2 . (See page 74.) 



258 DIRECTIONS FOR EXPERIMENTS. 



short time in the centre of the flame. On taking it out, minute beads of lead can 
be seen on the stick. Pulverize the end of the stick in a small mortar, and pour 
on some water. The pieces of charcoal can be washed away, leaving little bright 
spangles of lead, which flatten under the pestle. 

7. Repeat the experiment with a small quantity of copper oxide. The metal 
will require a stronger heat, but may be reduced in like manner. If the little 
bead be placed between two folds of paper, it may be flattened with the hammer, 
and will show the red color of copper. 

8. Select a sma.ll stick of charcoal, and with the point of a knife make a small 
cavity of the size of a split pea near one end. Put a little white lead in the cavity, 
and heat it strongly before the blowpipe in the reducing flame. A little bead of 
lead will easily be obtained, surrounded by a border of yellow lead oxide. The 
lead will flatten under the hammer. 

9. Take a glass cylinder open at both ends, and suspend 
near the top an inverted funnel which fits nicely into the cyl- 
inder. Place a turpentine lamp below it so that the smoke 
passes up into the funnel. When a considerable quantity of 
lampblack has formed on the sides of the cylinder and funnel, 
extinguish the flame and remove the lamp. Then slowly 
/ \ lower the funnel, the edge of which will scrape the lampblack 

from the sides of the vessel, in precisely the same manner that 
it is done by manufacturers in making lampblack for the 
market. 

7U-6. — 1. Break some marble into small bits ; place them 
carefully in the evolution-flask, and, inserting the cork and 
tube, pour in HCI slowly. The gas, on account of its weight, 
ffi ^ — -pi may be passed directly into a bottle or jar. 

2. Lower a lighted candle into a jar of the gas, or, placing 
the candle in an empty jar, pour the gas into the jar, as if it were water. Test the 
acid with blue litmus-paper moistened. 

3. In a pint of water place a piece of lime as large as an egg ; let it stand over 
night ; pour off the clear liquid ; it is lime-water. Place a little in a tumbler and 
breathe through it by means of a tube, or pass a current of C0 2 from the evolu- 
tion-flask until the liquid, at first milky, clears. 

4. Breathe through a tube into an empty bottle. Lower into it a lighted can- 
dle — it will be immediately extinguished. Pour in some lime-water, shake 
thoroughly, and it will become milky. 

5. Twist a wire around the neck of a small, wide-mouthed vial, to answer as a 
bucket. Lower it by the wire into a jar of C0 2 , our ideal well foul with the gas. 
Raise it again, and test for the C0 2 by means of a lighted match. The bucket 
will be found full of the gas. 

6. Balance a large paper bag or box on a delicate pair of scales, or in any 
simple manner one's ingenuity may suggest. Empty into the box a large jar of 
CO,, and the box will quickly descend. 

7. Arrange little wax-tapers in a wooden or pasteboard trough, as on page 75. 
Light them, and then pour in at the top a bottle of carbonic acid gas. If the 
proper slant is given to the trough, all the candles will be extinguished. 

8. To show the formation cf carbonic acid in the lungs, repeat Faraday's 
favorite experiment. Fit an open-mouthed receiver with a cork, through which 
passes a small bit of glass tubing. The receiver is then placed in a basin of water. 



DIRECTIONS FOR EXPERIMENTS. 250 

Expelling the air from his lungs, the experimenter inhales the air in the receiver 
through the tube. The water in the basin rises in the receiver, and shows how 
fast and when the air is exhausted. Breathing back the air from the lungs into 
the receiver again, the water is expelled, and the lighted taper will test the pres- 
ence of the carbonic acid. Before testing, the air may be breathed back and 
forward two or three times, until it becomes unpleasant. The rise and fall of the 
water in the jar is a pleasant and instructive addition to the experiment. 

SO.— i. Dry some potassium ferrocyanide, K 4 FeCy a , 3H 2 (prussiate of potash), 
till it crumbles down to a white powder. Mix 5 grams of this with 50 c. c. of oil 
of vitriol in a flask ; adjust a cork and a wide, bent tube to the mouth of the flask, 
and heat the mixture. The CO will come off very quickly, and will burn with a 
blue flame. Take care not to inhale it. 

2. Place a few crystals of oxalic acid (C a H 3 4 ) in a test-tube, pour on enough 
oil of vitriol to cover them, and then heat gently. Both CO and C0 2 will be 
evolved. On applying a flame to the open end of the tube, the CO will take Are 
and burn with a blue flame. To separate the two gases, pass them through a 
solution of KHO, which will remove the C0 2 , and the CO can then be collected 
over water. 

82. — 1. Introduce into a retort which will hold a litre, 15 c. c. of alcohol and 
60 c. c. of oil of vitriol. Heat the mixture, and collect the gas over water ; con- 
tinue the experiment until the mass blackens and swells up considerably. The 
product consists at first chiefly of defiant gas, mixed with ether-vapor ; but 
towards the end it becomes mingled with S0 2 . Pass it through a solution of 
potash, using a wash-bottle as shown in Fig. 13, and then collect in the gas-bag. 
Fit a piece of glass tubing, drawn to a fine point at one end, to the stop-cock of 
the gas-bag, by means of a bit of the rubber tubing. On turning the stop-cock 
and forcing out the gas, it may be ignited, when it will burn with a clear white 
light. 

2. Mix C 2 H 4 with twice its bulk of O and explode in soap-bubbles. It produces a 
greater noise even than the " mixed gases." Great care must be taken not to let 
the light approach the gas-bag containing the mixture. 

3. At the close of the first experiment, perform the one described in the note 
on page 89. A small piece of wire-gauze, four to six inches square, for this pur- 
pose can be purchased of any tinsmith. If you do not force the gas out too 
rapidly, you will be able to burn it on either side of the gauze at pleasure. 

4. Place on top of the gauze a piece of camphor-gum. Ignite it, and the flame 
will not pass through to the lower side. Then ignite on the lower side, and 
extinguish the flame on the upper side. 

83. Get a bit of bituminous coal about the size of a walnut. Pound it small, 
almost into dust. Fill an ordinary tobacco-pipe (one with a long stem is prefer- 
able), nearly full of the pounded coal, packing it down closely with your thumb- 
On the top press a disk of metal or a copper coin, and cover with a layer of plas- 
ter of Paris or some tough clay, reduced to the consistency of putty by being 
tempered with a little water. Heat the bowl of the pipe strongly, and a combus- 
tible gas will come out of the stem, which should now be held in a nearly vertical 
position. When no more gas is given off, and the jet of flame goes out, remove 
the clay or plaster covering. The residue in the bowl is coke. 

2. Place some bits of pine wood in a glass retort provided with a perforated 
cork and delivery-tube. Connect this with an empty wash-bottle. On heating 
the retort, gas is given off, tar collects in the wash-bottle (see p. 205), and char- 



260 DIRECTIONS FOR EXPERIMENTS. 

coal remains in the retort. The charcoal used for making gunpowder is prepared 
in this way in large iron cylinders. 

8U.—1. Fit a cork to a small test-tube. Take out the cork, and pass through it 
a bit of glass tubing drawn to a fine point at one end, so as to act as a gas-burner. 
Place in the tube fifteen or twenty grains of mercury cyanide ; replace the cork, 
and heat over a spirit-lamp. The test-tube may be supported by a strip of thick 
paper twisted around it at the top. Move the tube to and fro through the flame 
at first, until it becomes fully heated ; hold the tube inclined and not perpendicu- 
lar, letting the flame strike the side rather than the bottom. When the gas 
begins to come off, it may be ignited. 

2. To show the formation of potassium cyanide from a nitrogenous body. 
Take a thin piece of freshly-cut K, lay on it a bit of the nitrogenous substance, 
and cover with another thin piece of K. Press all tightly together ; drop the mass 
into a perfectly dry test-tube, and heat carefully until it melts and a flash of light 
is seen. When cold, break the tube, throw the fused mass into a clean test-tube, 
and make the test for KCy with FeS0 4 and Fe 2 CI 6 , or as given below. 

3. To test for the presence of potassium cyanide. Add to a solution of the 
suspected substance a few drops of solution of sulphate of iron and a slight excess 
of potash. Shake the precipitate a few moments with air in the tube, and add an 
excess of hydrochloric acid, when a blue precipitate, or a decided blue or green 
color pervading the liquid, will indicate the presence of a cyanide. Prussian blue 
is produced by this process. 

4. To show that there is no free hydrocyanic acid in the kernels of peach, 
cherry, and plum stones, or bitter almonds, but that it is formed on heating the 
same with water. Soak a long strip of Swedish filter-paper in a tincture of gum 
guaiacum (1 to 20), and dry. Next pass through a solution of sulphate of copper 
diluted 2000 times, when the paper will not be changed at all in color. Put a few 
freshly-pounded bitter almonds in a two-liter flask with water. On suspending 
in it the strip of test-paper above described, the paper will remain white ; but on 
pouring into the flask a single crushed bitter almond that has been warmed with 
water, the test-paper will at once be colored blue by the hydrocyanic acid gen- 
erated in the flask, without bringing the paper in contact with the liquid. 

85. — Take an ordinary argand lamp with an opening at the bottom to admit air 
at the centre of the flame. Raise the wick till it smokes. Apply the finger to the 
opening, and the flame becomes more dull and smoky. Remove the finger, and 
the flame brightens again. Now admit a jet of O at the opening, and the flame 
will whiten almost to the intensity of a lime-light. Great caution must be used, 
unless an oil-lamp be employed. The bright, clear flame shooting instantly 
through the cloud of smoke is very striking. 

86.— The structure of a flame is easily shown by taking a piece of white card- 
board about 3 inches square, and placing one edge against the wick of a lighted 
candle below the flame, and then bringing it quickly to a vertical position in the 
flame for an instant. On removing the card, there is burned on it a picture of the 
flame similar to Fig. 31. 

90. — Take the beak from a broken retort, draw out one end so that it will enter 
the air-hole b (Fig. 37) of a Bunsen burner. Place a turpentine lamp under the 
open end of the beak, held at an angle of 45 . The smoke enters the burner, and 
the non-luminous lamp becomes luminous, because the carbon is all burned. 

91.— 1. The compound blow-pipe with gasometers, as shown in Fig. 38, is a 
serviceable apparatus. If gas-bags are used, the one for H should be twice the 



DIRECTIONS FOR EXPERIMENTS. 261 

size of the one for 0. A board should be laid on each bag, upon which weights 
may be placed, when ready for use, so as to force out the gas steadily. Turn 
the stop-cock so that the H will pass out twice as fast as the O. Always ignite 
the H first, and then turn on the O slowly until the best effect is produced. If 
gasometers are used, press the inner receivers down to the bottom, and then 
pour in water until it reaches nearly the top. The rubber pipes may then be 
attached to the hydrogen or oxygen apparatus, and the gases passed directly 
into the gasometer. Proper pressure is produced, when the jet is to be ignited, 
by unloosing the strings from the inner receivers, and thus taking off the "lift" 
of the weights which equipoise them. Additional pressure is secured by bearing 
down upon the receivers. All the metals burn in the blow-pipe flame with their 
characteristic colors. Narrow slips should be prepared for this purpose. A 
mirror, and a cup for holding the chalk, are necessary to show the lime-light. A 
piece of hard chalk or lime, whittled to about the size of a pencil, may be held 
in the flame to illustrate the principle. 

99.— i. To a small gas-jar fit a good cork, through which pass a test-tube as 
shown in Fig. 42. Place the jar in a large beaker-glass or open-mouthed bottle, 
filled with spring water, which has been mixed with a fourth of its bulk of a 
solution of carbonic acid in water. Fill the tube with water, and place it in the 
neck of the jar, having introduced a few sprigs of mint or the leafy branches of 
any succulent plant ; then expose for an hour or two in direct sunshine. Bub- 
bles of gas will be seen studding the leaves ; and on shaking the jar they will 
become detached, and will rise into the test-tube. After a time the cork and 
tube may be withdrawn, keeping the mouth of the tube beneath the surface of 
the water ; then close it with the thumb, turn the tube mouth upwards, and test 
the gas with a glowing splinter. The wood will burst into a blaze, showing that 
the gas consists mainly of O. 

102.— 1. Put in the flask two ounces of NaCI and an ounce and a half of Mn0 2 . 
Pour on enough water to reduce the mixture to a thin liquid. Shake the flask 
until the whole interior is moistened. Insert the cork and delivery-tube ; the 
middle bottle (B), shown in Fig. 43, is not necessary. Fill the pneumatic tub * 
with strong brine or warm water \ using as small a quajitity as possible, since 
water absorbs the gas. Pour in an ounce of H 2 S0 4 through the funnel-tube (F), 
or directly at the nozzle, by removing the ground stopper, if a kind of flask be 
used which has one. The gas will come off at once, even before the heat is 
applied. Collect the gas in bottles and use directly, if convenient, otherwise put 
corks in them and rub the nozzles well with tallow.t Pass the gas through a 
tumbler of cold water ; this w^ill form chlorine-water, which should be bottled 
and kept in a dark place, or wrapped in black or yellow paper.:}: 

2. Plunge a lighted taper into the gas : it will burn feebly, with a red, smoky 
flame. 

3. Place a piece of dry phosphorus in a copper deflagrating-spoon ; introduce 
it into a bottle of C! : the phosphorus will take fire, and burn with a pale green- 
ish flame, while suffocating fumes of phosphoric chloride (PCI 3 ) are formed. 

* If this be large, use a tin pan in its place, and have a pail of warm water for 
filling the bottles. 

t A better way is to fill the wash bottle B with H 2 S0 4 and collect in dry glass 
stoppered bottles' by displacement. 

% If the water is cooled to 5 C. while the CI is passed into it, the whole be- 
comes a mass of crystals, hydrate of chlorine. 



262 DIRECTIONS FOR EXPERIMENTS. 

4. Dip a strip of blotting-paper into oil of turpentine ; plunge it into a 
jar of CI: it will immediately burst into flame, while a dense black smoke is 
given off. 

5. Powder some metallic Sb finely in a mortar, and sprinkle into a jar of CI : 
it will take fire as it falls, giving out fumes of antimony chloride (SbCI 5 ), which 
are very irritating. 

6. Pour a little boiling water upon some chips of logwood, so as to obtain 
a deep red liquid : add some of the solution of CI, and the red color will be 
discharged. 

7. Wrap a soda-water bottle in a towel ; fill it with water, and invert it in the 
pneumatic tub. Introduce a glass funnel into the neck, and having filled a jar 
of 100 c. c. capacity with CI, pass the gas into the bottle. Fill the same jar with 
H, and empty into the same bottle ; withdraw the funnel, close the neck with the 
palm of the hand, lift the bottle out of the water-bath, give it a shake to mix the 
gases, and apply a light. A sharp explosion will immediately follow, and 
gaseous HCI be formed. Equal measures of H and CI unite in this way, and the 
gas produced occupies the same bulk that its components did when separate. 
Sunlight will also cause the explosion of a mixture of CI and H. 

8. Fill a large jar with equal volumes of chlorine and olefiant gas (p. 82). 
Leave it standing for a while in diffused daylight ; oil drops will soon be seen 
standing on the sides of the vessel. It combines directly with the chlorine to 
form C 2 H 4 CI 2 , formerly called "The oil of the Dutch chemists." To this fact 
olefiant gas is indebted for its name, " oil builder." 

9. Mix together 2 volumes of CI and one of C 2 H 4 in a wide-mouthed jar, 
remove the cover and ignite. The CI combines with all the H, setting free all 
the C, which ascends as a thick black smoke. 

10. Burn H in CI, as shown in experiment of burning H in O. 

11. To show the manner in which CI acts as an oxidizing agent. To a solu- 
tion of MnSG 4 add lime water and CI water. It turns black from the formation 
of Mn0 3 . 

12. Print the word Proteus on a large card, first with the iodide-of-potas- 
sium-starch solution (note, p. 107), and second with a solution of indigo. The 
former will be white and almost invisible, the latter blue. Then paint the words 
(using a camel's hair brush) with a solution of chlorine. The first line will turn 
blue and the second white, thus just reversing their color. 

105—1. Melt 200 or 300 grams of NaCI in a clay crucible at a good red heat, 
and. when melted, pour out the salt upon a dry stone slab. On cooling, break 
the mass into pieces of the size of a pea, and preserve them in a dry bottle. 
Introduce 50 grams of the chloride, and about twice its weight of H 2 S0 4 , into a 
flask provided with a cork and bent tube. CI gas comes off, even in the cold, 
but it is extracted still more abundantly when heated. Collect the gas in dry 
bottles by displacement. It may easily be ascertained when the bottle is full, 
as a lighted taper will be extinguished if introduced. 

2. Fill a long-necked flask with the gas by displacement, close the neck with 
a perforated cork in which is a glass tube drawn out at the end, and immerse it 
in a basin containing infusion of litmus ; the blue liquid will rush into the flask, 
formin fe a fountain, and will become red. 

3. Fill a dry bottle by displacement with CI gas, and close the mouth with a 
glass plate. Withdraw the stopper from a bottle of the same size containing 
ammoniacal gas; invert the jar of CI over the one containing the H a N, and 



DIRECTIONS FOR EXPERIMENTS. 



26Z 



remove the glass plate. The two invisible gases will suddenly combine, a dense 
white cloud will be formed, and a solid salt produced. 

4. Dilute a little HCI with 6 or 8 times its bulk of water, and add caustic soda 
cautiously, until the liquid is neutral, and neither reddens blue litmus nor 
restores the blue to red litmus-paper. Pour the liquid into a basin, and evapo- 
rate it slowly ; crystals of NaCI will be deposited in cubes. 

5. Boil HCI in a test-tube with fragments of gold leaf: they will not be dis- 
solved. Now add a drop or two of HN0 3 : a yellow solution of gold chloride 
(AuCI 3 ) will be quickly formed. 

6. Fill a test-tube nearly full of pure rain or snow water, and add a drop or 
two of the nitrate of silver solution. A drop of HCI will cause a cloudy, white 
precipitate. * 

106.— 1. Grind in the mortar 3 or 4 grams of fluor spar, and mix with an equal 
weight of powdered glass. Introduce it into a flask previously fitted with a 
sound cork and a tube, as in the figure. Pour upon the mixture 30 grams of 
H 2 S0 4 , insert the cork and tube, and apply a gentle heat : a densely fuming gas 
is disengaged, consisting of 
silicic fluoride (SiF 4 ). This 
gas must not be inhaled, as 
it is very irritating. Pass it 
into a glass of H 2 0, having 
sufficient Hg at the bottom to 
cover the mouth of the deliv- 
ery-tube. Each bubble of 
gas as it rises is coated with 
a white film of hydrated 
silica, while the H 2 forms 
a solution of hydrofiuo- 
silicic acid (2HF,SiF 4 ). The 
deposit of silica would clog 
the tube if it were not for the 
Hg • hence the tube must be 
kept dry, which is best ac- 
complished by placing it in 
position in the Hg, then pour- 
ing water carefully into the 
glass on the i^g. Filter the 
solution and preserve it as a 
test for Ba and K. 

106. Fill a long vial half-full of water colored with bromine. Add ether to 
fill the vial. The ether w T ill float on the water and the vial will contain on top a 
colorless ana* at the bottom a red liquid. Shake the vial thoroughly, and, if the 
proportion of the ingredients be properly calculated, the ether will dissolve the 
bromine, and, on replacing the vial and giving time to settle, there will be a red 
liquid on top and a colorless one at the bottom. This illustrates the varying 
power of solution possessed by different liquids. 

* Well water which gives a considerable precipitate with AgN0 3 , is usually 
unfit to drink owing to sewage contamination. (See pp. 256, 60.) 




26Jf. DIRECTIONS FOR EXPERIMENTS. 

107. — i. Fill three test-tubes nearly full of soft water.* Pour in one a few- 
drops of a solution of mercuric chloride ; into the second, of sugar of lead ; into 
the third, of mercury subnitrate. Add to each of these a few drops of a solution 
of potassium iodide. The first especially will produce a brilliant color, mercury 
iodide ; the rapid change from yellow to red is very marked. On continuing to 
add the potassium iodide, the red precipitate will be dissolved and disappear. 

2. Make an additional quantity of mercury iodide. Let it settle. Pour off 
the liquid, and then spread the sediment on a piece of heavy card-board, making 
a red spot as large as a silver dollar. Dry it carefully. Then heat very strongly, 
when it will turn yellow. Rub over the yellow spot the point of a knife several 
times, bearing on very firmly, until a red mark can be seen. Lay away the 
paper for a day or two, and the red color will spread over the whole spot. 
As a variation of this experiment to show how using different quantities of a 
substance may produce different results. Fill a glass half-full of the scarlet 
mercury iodide ; also a larger glass with the potassium iodide solution. Pour 
the thick scarlet liquid into the transparent one, and the color disappears as if 
by magic, and a glass of apparently limpid water remains. Yet this second 
liquid which seems to swallow up the first was a part of the same which, when 
added to the mercury solution, originally produced the color. 

108. — i. Bend the end of a piece of thin platinum wire, 8 or io cm. long, into 
a small hook ; heat the wire to redness, and instantly touch with the wire a 
crystal of borax as large as a split pea ; it will adhere to the wire. Then intro- 
duce the wire and crystal into the flame of a spirit-lamp. The borax will swell 
up, become opaque and white, and will then melt into a clear, glassy bead. 

2. Touch the bead just made, with a wire moistened with a solution of cobalt 
nitrate. Then melt the borax again in the flame. A beautiful blue bead is 
obtained, which is almost opaque if the quantity of cobalt be considerable. If a 
scarcely visible fragment of manganese oxide be used, a violet bead is formed. 

3. Dissolve a few crystals of the boracic acid in a small dish with a teaspoon- 
ful of alcohol. Set fire to the spirit : it burns with a green flame, which is a good 
test for boracic acid. A similar green flame is obtained if a crystal of borax be 
moistened with glycerine and kindled as before. 

110. — i. Grind a little glass to a fine powder in a mortar ; place it on a piece 
of moistened red litmus-paper ; sufficient alkali will be dissolved by the water to 
tinge the paper. 

2. Mix a little fine sand with KN0 3 and Na 2 C0 3 , and heat strongly on a strip 
of Pt foil for 5 minutes. When cold it will dissolve in H 2 0. 

3. Take some of the silica obtained in the experiment of making 2HF,SiF 4 , and 
put it in a strong solution of KHO and boil. It will dissolve.t 

4. Take four glass cylinders 5 in. high, and pour into each about 1 oz. of 
ordinary water glass and 4 oz. of water. Drop into one a few crystals of iron 
sulphate, into another some crystals of blue vitriol, into the third white vitriol, 
into the fourth a crystal of each. Let them stand quietly for 24 hours. In the 
first, green fibers will be seen resembling very closely a growing plant ; blue and 
white ones will appear in the others. If closely corked they can be kept for weeks. 

* Melted snow, or very clear rain-water, will answer the place of distilled 
water in making solutions, etc., for experiments. 

t The infusorial silica, sold under the name of electro-silicon, will dissolve in 
KHO in the same manner. A basic silicate known as " water glass," or li soluble 
glass," is prepared in this way. 



DIRECTIONS FOR EXPERIMENTS. 265 

5. Pour 1 oz. of water-glass into a capsule and pour on it half as much H 2 S0 4 , 
taking care that the two do not mix. Pour immediately, but slowly, into a 
second capsule ; the silica separates in long tubes resembling stalactites. 

113. — 1. Melt a quantity of S, either the flowers or brimstone, in a test-tube. 
It is at first thick and dark-colored, but after continued heating regains its fluidity. 
Warm the side of the tube all the way to the top, and pour the liquid into water. 
It will form an elastic gum, which can be moulded into any desired form. 

2. Heat a piece of brimstone in a test-tube. After a little the S will sublime 
and collect in the upper part of the tube as flowers of sulphur. 

3. Fill a cup with brimstone and melt it with a gentle heat. Set it aside to 
cool. When a crust has formed on top, break it and pour out the liquid con- 
tents. If the cup be broken when cold, the bottom will be found covered with 
long crystals of S. 

4. Pulverize some brimstone and put in a test-tube and cover with CS 2 . Put 
the tube in warm water until the S dissolves, then cork it tightly, or, better, place 
it on a watch-glass under a bell-jar, and let it stand until crystals separate. They 
have a different form from those obtained from fusion. The more slowly they 
separate the larger they will be. 

5. Put a piece of S in a test-tube and above it some copper turnings or scraps. 
Heat the sulphur until it boils. The Cu burns brightly in the vapor of S. Fe and 
Pb will also burn in S vapor. 

HU.—i. S0 2 is conveniently prepared by heating H 2 S0 4 and Cu (Fig. 43), 
drying with H 2 S0 4 , and collecting by displacement, as it is quite soluble 
in water. 

117. — 1. Pour a little strong sulphuric acid into a test-tube. Place a splinter 
of wood in it : the wood will be blackened in a few minutes. Pour 1 c. c. of 
strong H 2 S0 4 into a tube containing 3 or 4 c. c. of water : considerable heat will 
be felt to attend the mixture.* Take a little of this diluted acid, and with a 
feather dipped into it trace a few letters upon writing-paper. Hold the paper 
near the fire : the water will evaporate, leaving the acid behind ; this will soon 
blacken the paper. 

2. Pour 1 oz. of strong H„S0 4 into 2 oz. H 2 0, and allow it to cool. Immerse 
in it a few sheets of dry unsized paper, remove and wash thoroughly. When 
dry they are very tough and stiff and resemble parchment. Wet a piece of this 
parchment paper and stretch it over the top of a beaker and tie it tightly. When 
dry it is perfectly smooth and firm. With the wet finger trace a letter upon a 
sheet of paper before putting it into the acid ; on taking it out the wetted portion 
drops out (p. 189). 

3. Dissolve some sugar in a very little water, so as to form a thick syrup. Put 
it in a tall beaker and pour on strong H 2 S0 4 until it begins to swell up and 
blacken. The H 2 S0 4 removes the H 2 from the sugar, leaving only C behind. 
(Note, p. 190.) 

4. Mix ^oz. H 2 S0 4 and 1 oz. pounded ice or snow. Stir it with a test-tube 
containing a little ether ; the ether soon boils. 

5. Mix 1 oz. H 2 SC\ with 4 oz. snow or pounded ice, and stir it with a test-tube 
containing cold water ; the water soon freezes. The vessel in which the experi- 
ment is performed usually freezes fast to the table so that it is well to set it on a 
plate or small board. 

* In mixing H.^SO^ and H 2 always pour the acid into the water. 



266 DIRECTIONS FOR EXPERIMENTS. 

6. Place in the evolution-flask half an ounce of FeS. Cover this with water, 
and then pour through the funnel H s S0 4 , until the gas comes off freely. It may 
be passed into a glass of cold water. This solution must be bottled and closely 
corked. The gas may be tested directly, as mentioned in the text. 

7. Add some of the solution to a dilute one of antimony tartrate: a beautiful 
orange-colored precipitate of antimony sulphide will be separated. With a dilute 
solution of tin chloride, a yellow, tin sulphide will be formed ; and with a solu- 
tion ot copper sulphate, also largely diluted, a brownish-black, copper sulphide 
will be obtained. (See Chapter on Qualitative Analysis.) 

118.— 1. Place a few drops of the disulphide in each of four test-tubes. To one 
add a little powdered sulphur, to a second a few minute scales of iodine, to a third 
a fragment of phosphorus, and to a fourth a few drops of water. Notice the beau- 
tiful color produced by the iodine ; the solution of the sulphur and the phos- 
phorus ; the insolubility of the liquid in water ; and also its refractive power. 

120. — 1. Cover a stick of phosphorus with dry, finely-powdered charcoal. It 
will soon ignite. 

2. Put in a vial half an ounce of sulphuric ether and a half-dozen pieces of 
phosphorus not larger than grains of wheat. Thoroughly shake and then set 
away. Repeat the shaking often. When the phosphorus is dissolved, pour a 
little of the solution on the hands, and when briskly rubbed together in a dark 
place they will glow with a ghostly light. 

3. Pour some of the solution on a lump of loaf-sugar. Drop this in hot water, 
when the ether will catch fire. 

4. Place a tew grains of KCI0 3 on a brick and pour over them some of the 
solution. The ether soon evaporates and the mixture explodes. 

5. Dissolve 1 or 2 decigrams of phosphorus in 2 c. c. of carbon disulphide in a 
test-tube ; pour a little of the solution upon a piece of filtering-paper, and allow 
it to dry? The phosphorus will be left in a finely divided form, and will set fire 
to the paper in a few minutes. The ether solution may be used instead. 

6. Place a bit of phosphorus in a solution of silver nitrate. In the course of a 
day or two it will be covered with brilliant crystals of reduced silver. Repeat 
with CuS0 4 solution. 

122.— 1. Dissolve 4 grams of caustic potash in 16 grams of water ; place it in a 
small flask of about 50 c. c. capacity, and add 2 or 3 decigrams of phosphorus ; 
immerse the delivery tube just below the surface of water in a small capsule, and 
heat the mixture gently. Bubbles of gas will form in the retort, and will break 
with a flash and a slight explosion upon the surface of the potash solution. By 
degrees the air of the retort will be deprived of all its 0, and then the bubbles of 
gas, as they escape into the air, will take fire, producing a white wreath of phos- 
phoric anhydride, which forms a series of ringlets, revolving in vertical planes 
around the axis of the wreath itself as it ascends.* 

12k. — 1. Boil 1 gram of arsenious anhydride with three of potassium carbonate 
in 100 c. c. of water till it is dissolved, and add it to a solution of 3 grams of cop- 

* There is danger of breaking the flask by the bursting of the bubbles of gas 
within it before the air has all passed out. A tea-spoonful of ether placed in the 
retort before the heat is applied will at once be vaporized, and will carry out the 
air. Great caution, however, is then necessary, as the ether-vapor is .very 
inflammable. A better way is to fill the flask and its delivery tube entirely with 
water. Still another method consists in fitting the flask with a second tube 
reaching to the bottom of the flask, and passing H gas through it both before and 
after the experiment. # 



DIRECTIONS FOR EXPERIMENTS. 267 

per sulphate in ioo c. c. of water : a beautiful green precipitate of ScheeWs Green 
(^CuHAsOJ will be obtained. 

2. Add a few drops of a solution of arsenious anhydride to 200 or 300 c. c. of 
water, and then 3 or 4 c. c. of HCI ; place in the liquid two or three slips of bright 
copper foil, and boil the whole for a few minutes : the copper foil will become 
coated with a steel-gray film. Part of the Cu becomes dissolved, and displaces 
the arsenic, which is thrown down on the undissolved portion. Pour off the 
water, dry the Cu on blotting paper, and heat the foil in a tube, sealed at one 
end. The arsenic will sublime, condensing in minute octahedra on the cold 
sides of the tube. This is ReinsctCs test for arsenic. (See note on p. 299.) 

3. Place 1 mg. of any As compound upon a fiber of asbestos and bring it into 
the upper part of a Bunsen gas-flame, which has only a small luminous point to 
it. Hold a dish of cold water an inch or two above the flame. The As burns to 
As a 3 and is deposited on the porcelain, but being white is invisible. Touch the 
spot with a neutral solution of AgN0 3 , then hold the stopper of the ammonia 
bottle near it, and blow some of the H 3 N vapor upon it. A yellow stain appears. 
Touch a drop of aqua-ammonia to it and it disappears again. 

4. Compounds of As when heated on charcoal give off a garlic odor. 

127.— 1. Before throwing K on water, carefully pare off all the crust that forms 
on it and remove the adhering naphtha. Pour a gill of water into a deep glass 
jar, throw in the K, and cover the jar to prevent accidents from flying pieces of 
the burning metal. View the flame through a piece of dark-blue glass. 

2. Burn some dry brushwood ; collect the ash, wash it with five or six times 
its bulk of water, and filter. Test the solution with a piece of reddened litmus- 
paper, which will become blue. Evaporate the solution to dryness in a small 
porcelain dish. If the dry mass be left exposed to the air for a few hours it will 
become moist. The potassium carbonate, of which it chiefly consists, attracts 
moisture rapidly and deliquesces. To a portion of the salt add a few drops of 
HCI : brisk effervescence occurs. 

3. Place 30 grams of pearlash in a half-litre bottle, and dissolve it in 250 c. c. 
of water. Shake 20 grams of quicklime with five or six times its bulk of water, 
and add the pasty mixture (about 120 c. c. in bulk) to the boiling solution of 
pearlash. Agitate the mixture, and let it stand till it is clear. Pour off a portion 
of the liquid : it is a solution of caustic potash. Add to it some HCI : no efferves- 
cence will occur. Agitate a tablespoonful of olive oil in a small vial with 3 or 
4 c. c, of the caustic solution dllmed with ten times its bulk of water: a milky- 
looking liquid will be formed, which is the first stage in the making of soap. 

4. Pulverize finely nitrate of potash and chloride of ammonium, five parts of 
each, and mix with sixteen parts of water. The temperature of the mixture will 
be reduced so low that if a test-tube with a little water in it be used to stir it, the 
water in the tube will be converted into ice. 

ISO.— 1. Pass CI gas into a solution of KHO ; yoi will have a solution of potas- 
sium hypochlorite, which possesses strong bleaching properties. Continue to 
pass in CI until it is no longer alkaline, when crystals of KCI0 3 will separate. 

2. If 4 measures of the cold saturated solution of potassium bichromate be 
mixed with 5 of oil of vitriol, and the liquid be allowed to cool, chromic anhydride 
crystallizes in crimson needles, which may be drained and dried upon a brick. 

131.— i. The salts of K and Na may also be distinguished in the following man- 
ner: To a pretty strong solution of the salt in question add a solution of tartaric 
acid, and stir the mixture with a glass rod. If K be present, white, gritty crystals 



268 DIRECTIONS FOR EXPERIMENTS. 

of cream of tartar (KH 5 C 4 6 ) will be deposited, but no such precipitate will 
occur with salts of Na. 

2. Make a saturated solution of NaCi and allow it tq crystallize slowly; hop- 
per-shaped crystals result. Better crystals are formed if the water contains a 
little sugar. 

3. Make a second solution and add MgCI 2 to it ; the crystals will be cubical. 

4. Take a small saucepan, and, having made a little pool of water upon a 
wooden stool, set the saucepan upon it ; then throw in a handful of snow or 
powdered ice, and a handful of common salt ; now stir with a stick, and the cold 
will freeze the saucepan to the stool, even before a large fire. 

133. Fill a tall cylinder with a clear saturated solution of NaCI, and pass into 
it at the same time strong currents of H 3 N and C0 2 gases. A precipitate of 
NaHCO, falls. This is known as the Solvay Ammonia soda process. The solu- 
tion contains NH 4 Cl, from which H 3 N may be recovered by treating it 
with CaO. 

137. — 1. Place a few lumps of black marble in the open fire, or in an open 
crucible with a hole at the bottom, and heat it strongly for an hour or two. 
When it is completely converted into quicklime, the lumps, when broken across, 
will be quite white. 

138.— 1. Into a tumbler of pure water pour a teaspoonful of lime-water and 
pass COo into it. At first it becomes milky owing to the formation of CaC0 3 , 
but the precipitate afterwards dissolves in the excess of C0 2 . Pour some of this 
clear solution into a test-tube and boil ; the C0 2 is expelled and the water 
becomes milky. Such water is said to be "temporarily hard." Fill a second 
test-tube with the clear solution and add a little lime-water ; a precipitate is also 
produced. Hard water may be softened either by boiling or, paradoxical as it 
seems, by adding lime-water. Water which contains CaS0 4 in solution is said 
to be " permanently hard," because it cannot be softened in this way. 

139. — 1. Select a medal suitable for the purpose ; paste a shallow rim of paper 
round it, so as to make it like the lid of a pill-box, and anoint the surface of the 
medal very lightly with oil. Mix a little of the dry plaster with water till it 
becomes of the consistence of thin cream ; apply it carefully with a hair-pencil 
to every part of the surface, so as to exclude air-bubbles ; then pour a thicker 
mixture into the mould. Allow it to remain for an hour. The cast may then be 
removed : it will be a reversed copy of the medal. 

11+1. — 1. Place a little of some magnesium salt on a platinum wire moistened 
with a solution of cobalt nitrate. A pink residue will be obtained on heating the 
wire in the outer part of a Bunsen gas-flame. 

2. Add to a solution of any magnesium salt, such as the sulphate, a solution 
of potash: a white precipitate of hydrated magnesia is formed. Excess of alkali 
will not re-dissolve it. Lime-water produces a similar precipitate. 

151.— 1. Allow a drop of HN0 3 to fall upon a slip of polished steel : a dark 
gray spot is produced, owing to the solution of the metal in the acid, while the C 
is left. If the acid be dropped upon a slip of iron a green stain is formed. 

2. Take a strip of steel (watch-spring, corset steel, or piece of hoop-skirt), and 
render it magnetic by rubbing with a magnet (Physics, p. 214). Dip it into iron- 
filings and hold them in an alcohol flame. They take fire and burn. 

3. Pulverize a salt of iron and heat it with Na 2 C0 3 on charcoal or on a 
match stick (p. 257). A black powder (Fe 3 4 ) is obtained, which is attracted by 
the magnet. 



DIRECTIONS FOR EXPERIMENTS. 269 

155. — i. Heat a bar of iron white-hot, and bring it in contact with a roll of S 
over a pail of cold water. The S and Fe immediately unite, and form drops of a 
reddish-brown color, which fall into the water. This is ferrous sulphide, FeS, 
useful in making H 3 S for laboratory purposes. 

2. Potassium permanganate (K a Mn a O„) may be obtained by mixing 40 grams 
of finely-powdered manganese dioxide with 35 grams of potassium chlorate, and 
adding a solution of 50 grams of caustic potash to the mixture, evaporating to 
dryness, and heating the powdered residue to dull redness in a clay crucible. 
When cold, the mass is treated with water, and decanted from the insoluble 
residue ; a splendid purple liquid is obtained, which on evaporation yields 
needles of the permanganate. 

3. Pulverize a few crystals of permanganate and dry them in a capsule held 
for a moment over the flame. Pour on them a few drops of the strongest H 2 S0 4 . 
Bring the dish in front of an H generator or direct against it a fine jet of illuminat- 
ing gas. The gas takes fire from the ozone liberated. 

4. Make a strong solution of the permanganate and heat to boiling in a test- 
tube. Pour in a few drops of glycerine ; the latter is oxidized so violently that 
a flash may be seen, and part of the liquid is ejected from the test-tube. 

5. The permanganate test for impure water. Take 4 parts of potassium per- 
manganate and 4 parts of potassium hydrate, and dissolve in 160 parts of freshly- 
distilled water. One minim of this solution placed in a test-tube of distilled 
water, remains of a beautiful pink hue for several days, but if the minutest trace 
of egg albumen be added to the same quantity of water, it will be infallibly 
detected. So, if on the addition of a minim of this solution to a wine-glass of 
water from any well used for drinking purposes, the water, after a few hours, 
gives a brownish precipitate with loss of color, such water contains an abnormal 
proportion of organic matter, and is injurious to health. 

157. Make a transparent solution of zinc sulphate (white vitriol) so abundantly 
formed in preparing H gas. Take a glass half-full of this solution and another 
half-full of strong ammonia. Pour them together, and if the proportion be 
properly calculated, the two liquids will form a solid so dry, apparently, that on 
inverting the glass containing it, not a drop will fall out. Cold will be produced 
by this change from a liquid to a solid state. (See Physics, p. 187.) 

158.— 1. Fill a test-tube nearly full of H u O. Pour in it a few drops of the 
solution of copper sulphate. Add H 3 N, and a blue precipitate will be formed. 
Notice the change from green to blue. The copper sulphate may be readily 
prepared for this experiment b}?- covering a copper cent with dilute oil of vitriol. 
This experiment may be made to show the divisibility of matter by weighing the 
cent, finding what proportion of the whole solution you use, and then experi- 
ment to see what quantity of water can be taken and yet have the blue color 
percepiible in the ammonia test. 

2. Besides the ammonia test for copper, the metal ma\^ be detected, (1) by the 
red metallic deposit formed on a polished plate of iron if dipped into a solution 
of the salt, (2) by the black insoluble sulphide produced by H 2 S, and (3) b}'- the 
blue hydrate turning black on heating. 

160. — 1. If a water contain lead, even in minute quantity, its presence is easily 
ascertained by taking two similar jars of 25 c. m. high, of colorless glass, filling 
both of them with the water, and adding to one of the jars 3 or 4 c. c. of a solu- 
tion of sulphuretted hydrogen. A quantity of lead less than one part in two 
millions is easily perceived by the brown tinge occasioned, on looking down upon 



270 DIRECTIONS FOR EXPERIMENTS, 

a sheet of white paper ; the jar to which the test has not been added serving as a 
standard of comparison. 

162. — i. Place a little gold leaf in two test-tubes ; to one add HN0 3 , to the 
other HCI. Even when heated, the gold leaf will remain unaffected in each. 
Pour the contents of one tube into the other : the Au will disappear with effer- 
vescence. Evaporate this solution in a small porcelain dish till the acid is nearly- 
all driven off: gold chloride will be left. 

2. Dilute the solution with 3 or 4 c. c. of H„0. To a portion of this liquid add 
a solution of ferrous sulphate : a brown precipitate of finely divided reduced Au 
is obtained, and iron chloride is formed. 

167.— 1. Dissolve a ten-cent-piece in HN0 3 . The solution has a bluish color, 
owing to the presence of the Cu. Dilute with 200 c. c. of water ; then add a solu- 
tion of NaCI so long as it forms a precipitate ; white flakes of silver chloride are 
formed. Stir the mixture briskly with a glass rod ; the precipitate will collect 
into clots. Filter the solution. The presence of Cu may be found in the clear 
liquor by adding to a portion of the liquid H 3 N in excess: a blue solution is 
formed. Place the blade of a knife in another portion of the filtrate ; it will 
become coated with metallic Cu. 

2. Take the precipitated silver chloride, and after having washed it well on a 
filter, place it in a wine-glass with a little water ; add two or three drops of 
H 2 S0 4 , and then place a slip of Zn in contact with the chloride, and leave it for 
twenty-four hours. The chloride will be reduced to metallic Ag, which will have 
a gray porous aspect, while zinc chloride will be found in solution. Lift out the 
piece of Zn carefully ; wash the Ag first with water containing a little HsSO^, then 
with pure H 2 0. Dry the residue. Place a small quantity of it upon an anvil, 
and strike it a blow with a hammer ; a bright metallic surface will be produced. 
Place a little of the gray powder upon charcoal, and heat in the flame of a blow- 
pipe: it will melt into a brilliant malleable bead. Dissolve another portion in 
HN0 3 ; red fumes will escape, and silver nitrate be obtained in solution. 

3. Fill a vial half-full of a solution of silver nitrate and add a few globules of 
Hg. The Ag will be precipitated in a few days, forming the " silver tree." 

4. Place a crystal of AgN0 3 on a piece of charcoal and heat in the reducing 
blow-pipe flame. The coal becomes covered with a film of metallic Ag. 

5. Float a sheet of sized paper on an NaCI solution. When dry, float it for 
3 minutes on a solution of AgN0 3 and dry in the dark. Press a fern leaf on a 
piece of glass, lay a sheet of this paper on it and then a thin board as large as 
the glass. Clamp them together with clothes-pins, and expose to direct sun- 
light. When sufficiently black place in a solution of " hypo," and wash for 
24 hours. 

6. In performing the experiment given at the bottom of p. 167, do not allow 
the solution to remain in the test-tube, but throw it away at once, as the black 
precipitate deposited, when dried, is powerful^ explosive and is known as ful- 
minating silver. 

191. — 1. Put a little AgN0 3 solution in a test-tube and add aqua-ammonia 
slowly until the brown precipitate has again dissolved. Pour some of this into 
a second test-tube and add a solution of grape-sugar. On boiling, the silver 
will be reduced in the form of a brilliant mirror on the side of the tube. 

2. Take a solution of CuS0 4 and add enough tartaric acid to prevent its being 
precipitated by KHO. Then add enough KHO solution to make it strongly alka- 
line. Pour some of this solution into a dilute solution of grape-sugar and boil. 



DIRECTIONS FOR EXPERIMENTS. 271 

The intensely blue color disappears and a red precipitate of Cu 3 is produced. 
This is called Nessler's test, and is employed to detect sugar in diabetic urine. 

198.— i. To one gill of water add fifteen or twenty grains of strong H 2 S0 4 . 
Place in a large flask and heat. While boiling, drop in slowly two drams of 
starch, finely powdered. Boil for several hours, adding water as may be neces- 
sary. Finally, drop in slowly fine chalk until the liquid is neutral ; then cool, 
filter off the calcium sulphate, and evaporate the liquid to a syrup. 

193.— i. Dissolve i oz. grape-sugar in io oz. of water and add a small quan- 
tity of yeast. Place the mixture in a flask connected by means of a glass tube 
with a second flask (Fig. 45) containing lime-water. Let it stand 24 hours in a 
warm place. The lime-water will become milky from the formation of CaCO. s . 
The contents of the flask will have an alcoholic odor, and by distilling, a dilute 
alcohol could be obtained. 

197.— 2. Mix together slowly 2 oz. of alcohol and 2 oz. of H.,S0 4 , and heat to 
150 C. in a retort connected with a cooler. Ethylic ether distills over. 

2. After washing out the retort used in the last operation, introduce into it 
3 oz. potassium acetate, 3 oz. alcohol, and 2 oz. H 2 S0 4 . Mix the alcohol and 
acid, and pour upon the pulverized salt ; heat gently. Ethyl acetic ether is 
formed. 

3. Heat a mixture of 2 oz. potassium acetate, 1 oz. H 2 S0 4 , and 1 oz. amylic 
alcohol. An artificial oil of pears is produced. 

199.— 1. Pour a little alcohol into a small beaker and suspend over it a strip 
of Pt foil which has been heated until it glows. It will continue to glow owing 
to a slow oxidation of the alcohol vapors. The peculiar penetrating odor 
observed is due to aldehyde. 

200. — 1. Marsh gas, CH 4 (p. 81), is made by heating a mixture of 2 parts 
sodium acetate, 2 parts KHO, and 3 parts powdered quicklime in a tube of 
hard glass or a metallic retort, a high temperature being required. 

2. Heat a mixture of NaCI, methylic alcohol, and H 2 S0 4 . A colorless gas, 
CH^CI, is obtained, which burns with a beautiful green flame. 

206. — 1. Mix together in a test-tube equal quantities of H a S0 4 and HN0 3 , and 
when cold, allow soma benzole * to flow into it, drop by drop. On pouring the 
mixture into water it will be found that the benzole no longer floats on water as 
before, and has acquired a very agreeable odor. An atom of H has been 
replaced by N0 2 , forming the poisonous nitro-benzole, C 6 H 3 N0 3 . 

SlU.—i. Dissolve 1 grain of quinine sulphate, in water acidulated with 
H 2 S0 4 . It exhibits in a dark room a beautiful fluorescence. Add chlorine-water 
and then aqua-ammonia ; a bright green color is produced, characteristic 
of this alkaloid. 

216. — 1. Fill three tall cylinders nearly full of water; to one add enough 
cochineal solution to color it faintly pink, to a second a little litmus. To each 
add some aqua-ammonia and then a solution of alum. In 24 hours a pink pre- 
cipitate is seen in the first, a blue in the second, and a white in the third, while 
the liquid in each has become colorless. These precipitates are called lakes. 
Dirty water becomes clear when treated with alum and ammonia. 

219. — 1. Fill a test-tube one-sixth full of sweet oil, add a little ammonia, and 
nearly fill with water. The constituents remain separate. Shake thoroughly, 

* Benzine from petroleum, does not possess this power of forming nitro 
compounds. 



DIRECTIONS FOR E X P E R 1 31 E N T S . 

and they will combine, forming a thin, soapy liquid. Add an acid, and they will 
separate at once. 

228. — The following experiment shows that albumen, in the presence of starch 
is not coagulated, even at a boiling temperature. It makes a fine class illustra- 
tion of catalysis. Mix 50 grains of pure starch with 1 fluid-ounce of water. 
Dilute the albumen of one egg to make 3 fluid-ounces and strain through muslin. 
Mix the two solutions and boil. There will be no coagulation or precipitate. 
Filter. Add a drop of nitric acid to the clear liquid, and instantly a dense white 
coagulation will be formed. 

229. — 1. Fill a test-tube one-third full of fresh milk and add an equal volume 
of water, then a little acetic acid (or rennet), and allow it to stand a short time ; 
filter out the precipitate and wasti with water. The precipitate consists of casein 
and fats. The filtrate contains sugar, as may be shown by its reducing action on 
an alkaline solution of tartrate of copper. Remove the precipitate from the filter 
and shake it up in a test-tube with ether. This dissolves out the fat. Filter 
again ; let the filtrate evaporate and the fat will be left in a pure state. 

2. Evaporate a larger portion of milk to dryness, and heat until the residue 
is quite white. Dissolve in water, filter and test for NaCI with AgN0 3 . 

230. — 1. Mix intimately 10 grains of gelatine with 50 grains of soda-lime, and 
heat strongly; NH 3 gas will be evolved and can be detected by its odor, its 
action on reddened litmus-paper, and by fuming with HCI. 

2. Make a dilute solution of gelatine and add a solution of tannic acid ; a 
leathery precipitate is formed (p. 211). 

3. Mix together equal volumes of a solution of gelatine and a solution of 
K 2 Cr 2 7 , and add a little tincture of logwood. Pour it into a flat dish and float 
upon it a sheet of unruled writing-paper and dry in the dark. Expose under a 
negative (p. 168) or fern leaves, to direct sunlight for an hour, then wash 
thoroughly with warm water. Bichromated gelatine is rendered insoluble by 
exposure to sunlight. This principle is employed in all photo-engraving 
processes. 

238.— A number of instructive experiments may be shown to prove the power 
of the sunbeam. 

1. Mix together equal volumes of dry CI and CO, and expose to direct sun- 
light. They combine quietly without explosion to form a colorless gas of pun- 
gent, suffocating odor, called Phosgene gas. The volume of gas formed is only 
half that of the gases employed. 

2. Mix together equal volumes of H and CI, in the dark, fill a small glass bulb, 
and throw it up into a bright beam of the sun, when it explodes with violence. Do 
not at any time hold the bulb in the hand or within several feet of the eyes. 

3. Plants decompose C0 2 in the sunlight. (See p. 99.) 

4. The ordinary photographic process, as given on p. 168, is a good illustra- 
tion of the power of the sun's rays ; also that given with gelatine on this page. 

5. Dissolve 1 gram of ammonia-citrate of iron in 20 c. c. of water ; add to it 
20 c. c. of a solution of K 4 FeCy 6 made in the same manner. Keep the mixed 
solution in the dark. Float a sheet of white paper on the solution and allow it to 
dry. Cover a plate of glass with black varnish, and before it dries write upon it 
with any sharp-pointed instrument. When perfectly dry, place it over a sheet of 
the prepared paper and expose two or three hours to bright sunlight. Remove and 
wash well in cold water. You will have the writing in blue on a white ground. 



QUALITATIVE ANALYSIS, 

FOR BEGINNERS. 



[The following pages on analysis were prepared by Edward J. Hallock, 
A.M., of Columbia College, N. Y.] 

In order to be able to analyze almost every inorganic substance 
met with in the arts, or sold in the shops, it is only necessary for 
the student to familiarize himself with the reactions of about twenty- 
six metals and a dozen acids. To be able to apply these tests with 
certainty, in all cases, and to know the easiest and best methods of 
dissolving the substance, constitute a qualitative chemist. 

For reasons which will appear farther on, metals are divided into 
five groups. 

The First Group embraces lead, silver, and the suboxide salts 
of mercury. They are classed together because they are the only 
metals whose chlorides are insoluble in acids. The student should 
take a solution of lead nitrate Pb (NO- 3 ) 2 , formed by dissolving lith- 
arge in nitric acid, or some lead acetate solution (see page 161), and 
try the following tests, making a note of his results. With HCl a 
white precipitate of PbCl 2 is formed. This precipitate is filtered 
out, washed, and dissolved in boiling water. To another portion 
of the solution add H 2 SO : , a white precipitate of PbS0 4 , insoluble 
in H 2 0. To a third portion add potassium bichromate, K 2 Cr 2 7 
(page 130) ; a yellow precipitate is formed. 

Repeat each of these tests with silver nitrate, AgNO. } {Experiment 

167)* The precipitate with HCl is insoluble in boiling H 2 0, but 

issolves in NH 4 HO. Repeat with mercurous nitrate, HgN0 3 , made 

by the action of very dilute HN0 3 on an excess of Hg, in the cold. 

* These numbers refer to the Experiments in the Appendix, 



27Jf QUALITATIVE ANALYSIS. 

We have with HC1 a precipitate of calomel (HgCl), (page 172), which 
is insoluble in H 2 0, and blackens on adding NH 4 H0, but does not 
dissolve. 

Separating Metals of Group I. — Mix the solutions of the three 
metals, and add HC1. Filter, and boil the precipitate in water; 
filter hot, and to the filtrate add K 2 Cr 2 7 . The yellow precipitate 
proves that lead is present. Boil the residue in ammonia and 
filter; to the filtrate add HN0 3 . A white precipitate proves silver 
present. The black insoluble residue is a compound of mercury 
(H g2 H 2 NCl). 

The Second Group embraces the protoxide salts of mercury, 
together with Pb, Bi, Cu, Cd, As, Sb, Sn, Au, and Pt. They are pre- 
cipitated from acid solutions, by H 2 S gas being passed through the 
solution, as sulphides. (See Experi?nent 117.) Of these HgS, PbS, 
Bi 2 S :3 , CuS, and CdS are insoluble in ammonium sulphide (NH 4 ) 2 S, 
and constitute the first division of this group. The sulphides of the 
remaining five metals are soluble in (NH 4 ) 2 S, and form the second 
division. (NH 4 ) 2 S is prepared, according to Fresenius, by saturat- 
ing a given volume of ammonia solution (specific gravity 0.96) with 
H 2 S gas, and adding to it an equal volume of the ammonia. The 
solution, which is at first colorless, soon becomes yellow by keep- 
ing, or may be at once converted into the yellow sulphide by the 
addition of sulphur. It should yield no precipitate with magnesium 
sulphate (Epsom salt). This reagent is decomposed by acid, sul- 
phur being precipitated. 

Pass H 2 S gas into a solution of corrosive sublimate (HgCl 2 ) ; a 
precipitate is formed which is at first white, then yellow, red, and 
finally black. It is insoluble in (NH 4 ) 2 S, and in HNO :3 . When dis- 
solved in aqua regia it gives a grey precipitate with SnCl 2 . Repeat 
the first experiment with some lead solution ; a black precipitate is 
formed, soluble in boiling HNO :3 . In this solution a white precipi- 
tate of PbS0 4 is formed on adding H 2 S0 4 . Add a few drops of KI 
solution to the original solutions of HgCl 2 , and Pb(NO :3 ) 2 ; in the for- 
mer case the precipitate (Hgl 2 ) is red, in the latter (Pbl 2 ) it is yellow. 
These tests are characteristic of the metals when alone. {Experi- 
ment 107.) Pass H 2 S into Bi(NO :3 ) :3 solution ;* a black precipitate ; 
dissolve in HNO :3 ; add a drop of H 2 S0 4 to prove it is not lead ; then 
cautiously add ammonia, which produces a white precipitate of 

* When Bi solutions are diluted with water, basic salts are precipitated unless 
there be too much free acid present. This reaction is most sensitive with BiCl 3 , 
so that HC1 may be used to dissolve the Bi(N0 3 ) 3 for the H 2 test. 



QUALITATIVE ANALYSIS. 275 

Bi(HO):,. Repeat all the above experiments with CdS0 4 solution; 
the precipitate with H 2 S is a beautiful yellow, soluble in HNO ;3 ,but 
insoluble in KCy. Pass H 2 S in CuS0 4 solution, and a brownish- 
black precipitate will be formed, soluble in HNO :3 and in KCy. 
Salts of copper have a bluish color, which becomes more intense on 
adding NH 4 HO. (Experiment 15S.) With potassium ferrocyanide 
(K 4 FeCy 6 ) they give a reddish-brown precipitate insoluble in HC1. 

Separating Metals of Second Group, First Division. — After 
the student has made all the above reactions he may mix the solu- 
tions of the five metals and proceed to separate them. Most of the 
lead is precipitated by HC1, and is filtered out before H 2 S is passed 
through the solution. The precipitate with H 2 S is boiled in HN0 3 , 
and HgS remains as a residue. When the solution is very acid, part 
of the H 2 S is decomposed and S precipitated, which must not be 
mistaken for HgS. To the filtrate add a little H 2 S0 4 to precipitate 
any lead present ; filter and add NH 4 HQ, when Bi(HO) :3 is precipi- 
tated. The precipitate, dissolved in aqua regia and concentrated by 
evaporation, should give a white precipitate if poured into water. 
The addition of NH 4 C1 aids this reaction. The blue filtrate from the 
Bi precipitate is boiled with KCy, care being taken not to inhale the 
fumes, and H 2 S added ; CdS forms a yellow precipitate. The pres- 
ence of Cu in the filtrate is proved by the formation of a reddish- 
brown precipitate with HNO-.J and K 4 FeCy 6 . 

The most interesting metal of group second, second division, is 
As. The sulphide is a beautiful yellow resembling Cd, but unlike 
Cd it is soluble in (NH 4 ) 2 S, and in (NH 4 ) 2 CO ;3 . The salts of arsen- 
ious acid yield with AgNO :J , yellow precipitates, Ag- ;3 AsO :3 soluble in 
HN0 3 . A small piece of bright green wall-paper usually contains 
enough of this metal to give several characteristic tests. Apply a 
single drop of nitric acid to the paper ; a moment after neutralize 
with ammonia and observe the color, a deep blue always indicating 
copper. When the white fumes have nearly disappeared, apply to 
the same spot a drop of AgNO ;3 ; a yellow ring indicates As. The 
most delicate test for As as well as Sb is Marsh's test (see page 124). 
The mirror formed by As on porcelain is soluble in bleaching pow- 
ders (see page 106), sodium hypochlorite, also called Labarraque's 
solution (see note, page 104), etc. ; that of Sb is insoluble in these 
(see note, page 173). If AsH :3 is passed into AgN0 3 , metallic Ag- is 
precipitated and enough HN0. 3 is set free to keep the yellow Ag- :3 AsO :3 
in solution until it is boiled with sodium acetate, when the precipi- 
tate reappears. 



276 QUALITATIVE ANALYSIS. 

Antimony closely resembles As in its reactions. Pass H 2 S into 
a solution of tartar emetic {Experiment 111 ', 3), and an orange-colored 
precipitate will pe formed, soluble in (NH 4 ) 2 S, but nearly insoluble 
in dilute (NH 4 ) 2 C0 3 . Put some of the first solution in a new Marsh's 
apparatus. The mirror formed is insoluble in bleaching powders, 
or sodium hypochlorite. If both As and Sb are suspected in the same 
solution, the gases AsH 3 and SbH 3 , formed by introducing the solu- 
tion into a hydrogen generator, are passed into AgN0 3 . The Sb 
forms SbAg 3 , which is precipitated with the metallic Ag, while the As 
remains in solution. The precipitate is filtered out, boiled in tar- 
taric acid, filtered, and H 2 S added to filtrate, when an orange-red 
precipitate proves the presence of Sb. To prove the presence of As, 
the filtrate from the Ag and SbAg 3 is boiled with sodium acetate to 
precipitate the yellow Ag 3 As0 3 as above mentioned. 

Gold and platinum are distinguished from all other metals by 
their insolubility in HC1 or HN0 3 , but are converted into soluble 
chlorides by aqua regia. The characteristic test for Au salts is SnCl 2 
mixed TVfth SnCT 4 , trie purple of Cassius being formed. FeS0 4 pre- 
cipitates metallic Au as a fine powder. (Experiment 16% ', 2.) PtCl 4 
is precipitated by KC1 as yellow K 2 PtCl 6 . Pt and Au give black pre- 
cipitates with H 2 S. Tin is soluble in HCl, but is oxidized by HN0 3 
without dissolving. There are two series of tin salts ; SnCl 2 gives 
a black precipitate with H 2 S ; SnCl 4 a yellow precipitate with H 2 S, 
both soluble in yellow (NH 4 ) 2 S. AuCl 3 is a test for Sn. SnCl 2 forms 
with an excess of HgCl 2 , a white precipitate of HgCl ; but when 
SnCl 2 is in excess a gray precipitate of Hg is formed. 

Separating Metals of Second Group, Second Division. — 
Into an acid solution of Au, Pt, Sn, Sb, and As, pass H 2 S gas; filter 
and dissolve precipitate in (NH 4 ) 2 S to remove any members of first 
division present. Precipitate the sulphides by HCl, and place in a 
hydrogen generator. The As and Sb combine with H, and are sep- 
arated as above by passing the AsH 3 and SbH 3 into AgN0 3 . The 
metallic Sn, Au, and Pt remain in the H generator ; the Sn is then 
dissolved out with HCl, and tested with HgCl 2 ; the Au and Pt are 
dissolved in aqua regia and tested in separate portions of the solu- 
tion as above described. 

Group Third embraces Co, Ni, Fe, Cr, Mn, U, Al, and Zn. They 
are precipitated by (NH 4 ) 2 S from neutral or alkaline solutions. 
The characteristic test for Co, is the blue color imparted to a borax 
bead. (Experiment 108.) Ni alone gives, in the outer blow-pipe 
flame, a reddish-brown bead. Both give with (NH 4 ) i S black preci- 



QUALITATIVE ANALYSIS. 277 

pitates insoluble in dilute HC1. If KN0 2 and acetic acid are added 
to a solution of Co and Ni, the former is slowly precipitated and 
not the latter. To a solution of FeS0 4 , add a drop of potassium 
ferricyanide (K 6 Fe 2 Cy 12 ); a blue precipitate is formed. To an- 
other portion add (NH 4 ) 2 S ; a black precipitate is formed, soluble in 
dilute HC1, from which solution it is re-precipitated by NaHO, as 
Fe(HO) 2 . Repeat the latter test with ferric chloride (Fe 2 Cl 6 ) and 
the same result is obtained. Fe 2 Cl 6 gives with K 4 FeCy 6 a precipi- 
tate of Prussian biue. Into a glass of water place one drop of 
Fe 2 Clfc, and add potassium sulphocyanide (KCyS) ; the liquid acquires 
a beautiful red color. Iron salts also give characteristic colors to 
the borax beads. To a solution of MgS0 4 , add (NH 4 ) 2 S ; a flesh- 
colored precipitate is formed, soluble in HC1, re-precipitated on 
boiling in NaHO, as Mn(HO) 2 . The borax bead with Mn acquires 
an amethyst-red color (see note, page 109) in the outer blow-pipe 
flame. Fused with Na 2 C0 3 and KN0 3 a green mass is formed. 
(NH 4 ) 2 S gives with compounds of Cr, a greenish precipitate of 
Cr 2 (HO) 6 , soluble in HC1, and re-precipitated by NaHO. Fused with 
Na 2 C0 3 and KN0 3 it forms a yellow mass. With Pb(N0 3 ) 2 it gives 
a yellow precipitate. Uranium gives with (NH 4 ) 2 S a black precipi- 
tate, soluble in HC1, re-precipitated by NaHO, which precipitate is 
soluble in (NH 4 ) 2 C0 3 . With K 4 FeCy 6 it yields a red precipitate. 
(NH 4 ) 2 S produces in solutions of Al salts a white precipitate, solu- 
ble in HC1, from which it is re-precipitated by NH 4 C1, but not by 
NaHO. In salts are also precipitated white by(NH 4 ) 2 S; the pre- 
cipitate is soluble in HC1 and not re-precipitated by NaHO. After 
the student has carefully repeated all the tests above given, he is 
prepared to undertake the 

Separation of Metals of Group Third. — Some NH 4 C1 and 
NH 4 HO is first added to the filtrate then (NH 4 ) 2 S. The precipi- 
tate is digested in dilute HC1 ; Ni and Co are sought in the residue. 
The filtrate is boiled with NaHO for half an hour in a porcelain 
capsule, and filtered. The filtrate is divided in two portions, to 
one of which NH 4 C1 is added to precipitate Al, to the other H 2 S to 
precipitate the Zn. The residue is boiled in (NH 4 ) 2 C0 3 to dis- 
solve U, which is tested with K 4 FeCy 6 . The residue, containing Fe, 
Mn, and Cr, is fused with pure KN0 3 and Na 2 C0 3 ; if the mass is 
green, Mn is indicated ; if yellow, Cr. One-half of the mass is dis- 
solved in water ;' the insoluble residue is tested for iron ; the 
filtrate is tested for Cr by first neutralizing with acetic acid, and then 
adding Pb(N0 3 ) 2 . TJie test for Mn is to place some of the fused 



278 QUALITATIVE ANALYSIS. 

mass in HNO ;j with red lead ; if left at rest, a beautiful rose pink 
is formed from the reduction of K 2 Mn0 4 to K 2 Mn 2 8 . {Experiment 
loo, 2.) 

Group Fourth embraces the metals of the alkaline earths, Ba, 
Sr, and Ca, whose carbonates, precipitated by (NH 4 ) 2 C0 3 are in- 
soluble in hLO, but soluble in HC1. BaCl 2 forms with H 2 S0 4 a 
precipitate insoluble in acids ; it is also precipitated by hydrofiuo- 
silicic acid (2HF,S!F 4 ), {Experiment 106), more easily in presence of 
alcohol. Ba compounds impart a green color to the flame of an 
alcohol lamp or Bunsen burner. CaCl 2 with ammonium oxalate, 
yields a white precipitate insoluble in water. H 2 S0 4 produces a 
white precipitate of CaS0 4 , slightly soluble in water and acids. Ca 
salts color the flame yellowish-red. SrCl 2 gives a white precipi- 
tate with a clear solution of CaS0 4 ; if the solution is dilute, half 
an hour is required for the precipitation. Sr colors the flame car- 
mine-red. 

Separating Metals of Group Fourth. — Some NH 4 C1 is first 
added, if not already present in the solution, then (NH 4 ) 2 C0 3 . The 
precipitate is dissolved in HC1, then alcohol and 2HF,S!F 4 are added 
until all the Ba is thrown down. The solution is then divided, and 
to one portion NH 4 HO and CaS0 4 is added ; SrS0 4 separates in 
half an hour. To the other portion H 2 S0 4 is added, and a 
precipitate of SrS0 4 and CaS0 4 filtered out ; the filtrate is then 
tested for Ca with ammonium oxalate. 

Group Fifth embraces Mg, K, Na, and L As lithia is very rare, 
we omit its reactions. MgS0 4 yields a white precipitate of Mg(HO) 2 t 
on the addition of NH 4 HO, unless the soTution contains NH 4 CI ; 
hence the necessity of adding NH 4 CI, before testing for Groups III 
and IV, where NH 4 HO would otherwise throw down Mg. The 
salts of Mg give a white precipitate with hydrodisodic phosphate, 
Na,HP0 4 and NH 4 H0. KCI yields a yellow precipitate with PtCI 4 . 
Potassium acetate is also precipitated in concentrated solutions by 
tartaric acid. K 2 S0 4 gives a white precipitate with 2HF,SiF 4 and 
alcohol. K imparts a violet color to flame, which appears red when 
viewed through blue glass. Na is not precipitated by any of the 
above reagents ; but may give with NaSb0 3 a white precipitate. It 
imparts an intense yellow color to flame. K, Na, and L, as well as 
Ca, Ba, and Sr are easily detected by the spectroscope. 

Ammonia is liberated from its compounds by mixing with NaHO 
or Ca(HO) 2 , and is then recognized by the smell, by bluing red 
litmus, and by producing white fumes when a rod moistened with 
HCI is held over it. (See pages 49, 135.) 



QUALITATIVE ANALYSIS. 279 



TESTS FOR ACIDS. 

The acids do not admit of the strict grouping and successive 
separation employed for metals, and we will rest content with men- 
tioning the simplest tests for the principal acids, beginning with 
the haloids : 

HC1 with AgN0 3 , white precipitate, soluble in NH 4 HO. 

HI " " yellowish precipitate, insoluble in NH 4 HO. 

HI " HgCl 2 , red precipitate, soluble in KI. 

HI " starch paste and CI solution or bleaching powders, blue 
color. (See page 107.) 

CaF 2 with H 2 S0 4 liberates HF, which attacks glass. (See p. 106.) 

HBr " starch paste and CI water, an orange-yellow color. 

H 2 S0 4 with BaCI 2 , white precipitate, insoluble in HCI. 

Si0 2 is insoluble in H 2 0, as are most of the silicates except 
those of K and Na. In analyzing the soluble silicates, they are 
first evaporated to dryness with excess of HCI, the soluble chlorides 
dissolved in H 2 or HCI, and the Si0 2 left as a gritty powder. 

Boracic Acid is detected by placing it in a capsule containing 
alcohol and H 2 S0 4 , and igniting the alcohol. A green tinge to 
the flame indicates Bo. (See page 109.) If a solution of an alka- 
line borate is mixed with HCI until slightly acid, a slip of turmeric 
paper dipped in it and dried at 212 , acquires a peculiar red 
tint. 

H 3 P0 4 with AgN0 3 , yellow precipitate, soluble in HN0 3 . 

11 solution of ammonium molybdate in HN0 3 , fine yel- 
low precipitate. 

H 3 P0 4 with MgS0 4 , solution containing NH 4 C1 and NH 4 HO, a 
white precipitate soluble in acids. (See test for Mg, page 278.) 

C0 2 . Carbonates effervesce on the addition of acids, C0 2 being 
set free, which extinguishes a match inserted in the test tube. 
The ear is often able to detect slight effervescence not otherwise 
perceptible. (See page 74.) 

HN0 3 is not precipitated by any reagent. Into a test-tube con- 
taining some nitrate, drop a crystal of FeS0 4 , then allow a drop of 
H 2 SO i to flow down the side of the test-tube which is held in- 
clined. A dark-brown ring of sesquioxide forms immediately. 
If Cu and strong H 2 S0 4 are heated with a nitrate, red fumes are 
given off. A nitrate heated on charcoal deflagrates. 



280 QUALITATIVE ANALYSIS. 

Chlorates deflagrate more violently than nitrates. H 2 S0 4 liber- 
ates C10 2 which is betrayed by its color and odor. If a crystal of 
KCIO3 and a piece of P be placed in a glass of water, and a drop 
of H 2 S0 4 conveyed to it by a pipette or tube, the P takes fire 
and burns under water (page 130, Experiment 2). All experiments 
with chlorates must be performed with minute quantities, because 
of the great danger of explosions. 

SO 2 is easily recognized by its odor. When sulphites are treated 
with HC1, the S0 2 is evolved. 

If CI gas be given off on heating a substance in HC1, the pres- 
ence of a binoxide may be suspected. (See page 103.) 

HCy with AgN0 3 , white precipitate soluble in KCy ; difficultly solu* 
ble in NH 4 HO. If FeS0 4 and a little Fe 2 Cl 6 are added to a solution 
of a cyanide acidified with HC1 no change takes place, but on add- 
ing KHO a bluish-green precipitate is formed. Care must be taken 
in handling the poisonous cyanides. On adding HC1 to a cyanide, 
HCy is liberated, and is detected by the odor, which resembles bittei 
almonds. 

H 4 FeCy 6 with AgN0 3 , white precipitate insoluble in NH 4 HO, and 
in HNO3. With Fe 2 Cl b , or any other ferric salt, Prussian blue 
[Fe 4 (FeCy 6 ) 3 ] is formed. Insoluble ferrocyanides are decomposed 
on boiling with KHO, forming K 4 FeCy 6 ; and the metallic oxide, if 
insoluble in KHO, is precipitated. 

H 6 Fe 2 Cyi 2 with AgN0 3 , orange-colored precipitate soluble in 
NH 4 HO and KCy. With FeS0 4 , or any other ferrous salt, a blue 
precipitate is formed. KHO decomposes insoluble ferricyanides. 

Oxalic Acid, H 2 C 2 4 , yields a white precipitate with CaCl 2 , which 
is insoluble in NH 4 C1. 

Citric Acid, H 3 C 6 H 5 7 , also yields a white precipitate with CaCl 2 , 
but unlike the above it is soluble in NH 4 C1, and insoluble in KHO. 
On boiling the solution in NH 4 C1, an insoluble citrate of lime 
separates. 

Tartaric Acid, H 2 C 4 H 4 6 , is precipitated by CaCl 2 in excess. 
The precipitate is soluble in cold KHO, and is re-precipitated on 
boiling, and redissolved on cooling. KC 2 H 3 2 (formed by adding 
acetic acid to K 2 C0 3 and filtering) precipitates tartaric acid, if both 
solutions are strong. Pb(C 2 H 3 2 ) 2 also produces a precipitate. 

Acetic Acid, C 2 H 4 2 , is usually detected by the odor given off on 
heating it with equal volumes of H 2 S0 4 and pure alcohol. If 
Fe 2 Cl 6 is added to a hot solution of an acetate, a dark-red color is 
produced. 



QUALITATIVE ANALYSIS. 281 



PRELIMINARY TESTS. 

A few tests in the dry way will give some clew to the substances 
present ; but in a complete analysis every acid and every metal must 
be sought for. 

I. Heating in a Tube of Hard Glass closed at one end. — 
If the substance blackens, organic matter is present. If vapors 
escape, they are tested for C0 2 , S0 2 , H 2 S, etc. If a sublimate is 
formed, it may be S, Hg, or a compound of As or Sb. 

II. Heating on Charcoal. — A small portion of the substance 
is placed on charcoal and exposed to the inner blow-pipe flame. 
(See page 69.) If an infusible white residue remains, moisten it 
with Co(N0 3 ) 2 ; a fine blue indicates Al, a reddish tint Mg, a green 
color Zn. Mix another portion with Na 2 C0 3 and heat on charcoal 
in the reducing flame. If a metallic globule is formed without an 
incrustation, it indicates Au, Cu, or Ag, as the color is yellow, red, or 
white. A very fusible and malleable globule surrounded by a yel- 
low incrustation indicates Pb ; if the incrustation is white it may be 
Sn, and on moistening with Co(N0 3 ) 2 the incrustation turns green. 
Bi and Sb may be reduced to brittle metallic globules. If As is 
present, an odor resembling garlic is noticed. The charcoal tests 
will be of little use to the student, except for detecting Ag and Pb, 
until practice has given him considerable facility in the use of the 
blow-pipe. 

III. Borax Beads. — Several metals impart characteristic colors 
to borax glass when fused with it before the blow-pipe. The opera- 
tion is a very simple one, and many of the beads can be made in 
even an ordinary gas or alcohol flame without the use of a blow- 
pipe. The end of a piece of platinum wire is bent to form an eye 
as large as this letter O ; it is next dipped in borax and held in the 
flame until fused, then dipped in the powdered substance and fused 
again. Cr in O.Fl.* imparts a yellow or red color when hot, which 
becomes yellowish green on cooling ; in R.FL* the glass is green 
hot and cold. Co in both flames blue. Cu, in O.Fl. green while hot, 
blue when cold. Fe in O.Fl. yellow to red when hot, colorless 01 
yellow when cold ; in R.FL bottle green. Mn in O.Fl. violet or ame- 
thyst ; in R.F becomes colorless. 

* O.Fl.= oxidizing flame ; R.F1.= reducing flame (page 92). 



282 QUALITATIVE ANALYSIS. 



SOLUTION. 

The first thing to be done before beginning an analysis is to 
bring the substance into solution. Distilled water is first employed ; 
if a residue insoluble in water remains, it is treated with acid. In 
analyzing metals and alloys, nitric acid is the usual solvent ; aqua 
regia being required only for the noble metals. If Sn is present, 
and Pb and Ag absent, HC1 is employed. Mineral substances, if 
insoluble in any acid, are rendered soluble by fluxing, or fusing 
with pure Na 2 C0 3 and K 2 CO :3 . As a very high heat is required for 
fluxing, deflagration is sometimes preferred. One part of the insol- 
uble powder is intimately mixed with two parts of dry sodium car- 
bonate, two parts pulverized charcoal, and twelve parts nitre. The 
mixture is placed in the open air and a match applied. A portion 
of the porous mass produced will be soluble in water, the remain- 
der in acids. The two solutions are to be preserved and tested 
separately. The metals will be found in the acid solution, while 
the acids will be found in the aqueous solution. Before beginning 
the regular course of analysis with these solutions, part of the 
aqueous solution is evaporated to dryness with excess of HC1 to 
render all the Si0 2 insoluble. In separate portions of the aqueous 
solution, the various acids are sought as above described (p. 279). 

If a portion of the substance is insoluble in HC1 after fluxing, it 
is probably silicic acid, or an undecomposed silicate, and may be 
rendered soluble by fluxing a second time. 

A platinum crucible must never be employed if reducible metals, 
especially Pb, have been found in the preliminary tests. 

EXAMPLES FOR PRACTICE. 

After the student has made all the tests above given, and suc- 
ceeded in separating the members of each group from each other, 
especial care being given to the separation of lead from bismuth, 
copper from cadmium, arsenic from antimony, and nickel from 
cobalt, the teacher may give out the following or similar substances 
for analysis, not following the precise order of the book, so that the 
student shall not know what substance he is analyzing. Each stu- 
dent should record the results of every analysis in a note-book 
which he will rule for each analysis as shown under No. 1. 

1. Analysis of CuS0 4 . — A crystal of this salt as large as a pea 



Q UALITATIVE ANAL YSIS. 



283 



is given to a student, who dissolves it in distilled water in a test 
tube and divides the solution in two portions. To one is added a 
drop of HC1, which should produce no precipitate. H. 2 S is then 
added until all the Cu is precipitated. It is then filtered and the 
precipitate thoroughly washed on the filter. H 2 S should produce 
no precipitate in the filtrate. The precipitate being insoluble in 
(NH 4 ).,S, is dissolved in HN0 3 , and no residue, except perhaps a 
little sulphur, remains, so that the absence of Hg is established. 
H 2 S0 4 produces no precipitate in this solution, neither does 
NH 4 HO ; hence Pb and Bi are also absent. The ammonia, however, 
gave the intense blue color characteristic of Cu, and as only one 
metal is to be sought, the presence of Cu is farther proved by adding 
HNO ;3 and K 4 FeCy 6 , which causes a reddish-brown precipitate. 
The second portion of the solution is used in testing for acids. To 
a small quantity of this some BaCl 2 is added, and if the precipitate 
is insoluble in HC1, the acid present must be H 2 S0 4 . The results 
are recorded in tabular form thus : 

ANALYSIS NO. I. 
Substance blue, soluble in H 2 0. 



GROUP I. 


GROUP II. 


GROUP III. 


GROUP IV. 


GROUP V. 


HC1 


H 2 S 


(NH 4 ) 2 S 


(NH 4 ) 2 C0 3 







Brown pre- 
cip., sol. in 
HNO3. 

NH 4 HOblue. 

K 4 FeCy 6 

brown. 

Cu. 












Acids : 
BaCl 2 . White precipitate insol. in HC1 .... H 2 S0 4 . 



2. Analysis of HgCL. — This salt is likewise very soluble in 
H 2 0. To one portion of the solution add HC1, and H 2 S. The lat- 
ter produces a black precipitate, insoluble in HNO3, which indicates 
Hg, but a confirmatory test must be employed, which is to dissolve 
the precipitate in aqua regia and add SnCl 2 . To a second portion 



28Jj. QUALITATIVE ANALYSIS. 

add some BaCl 2 , which will cause no precipitate. To a third por- 
tion add AgN0 3 , which produces a white precipitate of AgCl, insolu- 
ble in HN0 3 , but soluble in NH 4 HO, and this proves that the acid 
is HC1. 

3. Analysis of FeS0 4 . — Acidify a portion of the solution with 
HC1, add a little H 2 S to prove that no metals of the second group 
are present, and then (NH 4 ) 2 S, which produces a black precipitate 
of FeS, which is treated as directed for Group III, page 277. To 
some of the original solution a drop of K 6 Fe 2 Cy 12 is added, when 
the blue color proves the presence of Fe. The acid is found as in 
No. 1 with BaCl 2 . 

4. Analysis of Sr(N0 3 ) 2 . Dissolve in water, test for Groups I, 
II, and III, which may occur as impurities, and then add (NH 4 ) 2 C0 3 . 
This white precipitate is filtered out and washed, then dissolved in 
pure HC1. To one portion add 2HF,SiF 4 and alcohol, when the 
absence of Ba is shown, and the Sr test may next be made, by add- 
ing NH 4 H0 and CaS0 4 . The precipitate forms slowly. In the 
original solution no precipitate is formed by BaCI 2 or AgN0 3 , and 
a careful test for HN0 3 is made with FeS0 4 and H 2 S0 4 , as de- 
scribed on page 279. 

5. Analysis of BaS0 4 . — This substance refuses to dissolve either 
in H 2 or in acids. It is boiled repeatedly with fresh quantities 
of Na 2 C0 3 and filtered boiling hot. The filtrate contains Na 2 S0 4 ; 
the residue is BaC0 3 and unaltered BaS0 4 . The residue is dis- 
solved in HC1 and tested for with 2HF,SiF 4 or SrC0 4 solution. 

6. Analysis of a Coin. — A silver coin is dissolved in HN0 3 , 
then diluted and the Ag precipitated with HC1 as AgCl. From this 
metallic silver is precipitated on a piece of clean zinc placed in the 
precipitate and moistened with dilute H 2 S0 4 . In the blue filtrate 
will be found all the copper, which may be tested for as above. If 
instead of a silver coin, a nickel coin is used, HC1 will give no pre- 
cipitate, the Cu will be thrown down by H 2 S, and the Ni by (NH 4 ) 2 S. 
In analyzing compound substances, great care must be taken that 
all the metals of a certain group are precipitated before proceeding 
to the next, and for this purpose, after precipitating the Ag with 
HC1, a drop of HC1 is added to the filtrate to ascertain whether any 
Ag remains in solution. 

7. Analysis of Type Metal. — The type is cleaned and dissolved 
in nitric acid. If a white insoluble residue remains, it may contain 
both tin and antimony. To the filtered and diluted solution add 
just enough HC1 to precipitate all the Pb, and filter cold. To the 



QUALITATIVE ANALYSIS. 285 

filtrate add H 2 S as long as a precipitate is formed. Filter and wash 
thoroughly, digest with (NH 4 ). 2 S and filter. Dissolve the residue 
in HN0 3 and test for Pb and Bi. To the (NH 4 ) 2 S solution add 
excess of HC1 to ascertain whether any portion of the precipitate 
was really dissolved. An orange red precipitate indicates Sb, which 
may be farther tested in a Marsh apparatus. The white residue, 
which was insoluble in HN0 3 , is placed in a porcelain dish in con- 
tact with a slip of clean, smooth platinum foil, and heated with a 
little HC1. H 2 is then added, and a small fragment of Zn is put 
into the liquid, when Sn and Sb will be reduced to the metallic state. 
If the foil is blackened, Sb is present. The metallic residue is now 
dissolved in HC1, and HgCl 2 is added to ascertain if Sn is present. 

8. Analysis of Tea-lead. — This substance, which is used by the 
Chinese for lining tea-chests, may be obtained of any retail grocer, 
or tea merchant. It consists of lead, tin, and copper, and the course 
of analysis differs little from that of type metal. 

9. Analysis of Mixed Salts. — A mixture of Pb(N0 3 ) 2 , Bi(N0 3 ) 3 , 
Co(N0 3 ) 2 , KN0 3 may be dissolved in water and the metals sought 
in the above order (viz. Pb, Bi, Co, K). In testing for acids the 
student will remember that if Pb was found among the metals, 
H 2 S0 4 and HC1 must have been absent, as either would have pre- 
cipitated the lead. If the student forgets this and adds^ BaCl 2 to 
the solution, it will form a precipitate of PbCl 2 , which he might 
mistake for BaS0 4 , and hence incorrectly suppose H 2 S0 4 to be 
present. 

Mixtures of various other soluble salts should now be given out, 
such as FeS0 4 , NaCl, CuS0 4 , and NH 4 C1 ; gradually increasing the 
number of metals and acids to be sought. 

10. Analysis of Lime-stone. — Dissolve any piece of marble or 
lime-stone in HC1. It will not be necessary to test for groups 1 
and 11; a small portion of the solution is tested with K 4 FeCy 6 for 
iron. The alumina generally present is precipitated, along with 
the iron, by NH 4 HO, after adding NH 4 C1, and is filtered out as 
rapidly as possible. In a small portion of the filtrate tests are made 
for Ba and Sr, which are of course absent, so that all the Ca may be 
precipitated by oxalate of ammonia. In the filtrate Mg will be 
found on adding Na 2 HP0 4 . The principal acid present is C0 2 as 
indicated by the effervescence with HC1 when first dissolved. If a 
residue remained insoluble in HC1, it is probably Si0 2 , or some 
silicate, and must be fluxed with Na 2 C0 3 and K 2 C0 3 . 



286 



QUA LIT A TIVE ANALYSIS. 



TABLE I.— SCHEME FOR 



Add HCl to Solution. 
PREC. 



FILTRATE. 



Ag Pb Hg 


, 


Add H 3 S. 


Boil in H 2 




PRECIPITATE. 


Sol. Free. 






Pb 


AgHg 
NHJ30 




Hg Pb Bi Cd Cu As Sb Sn Au Pt S. 




Digest with (NH 4 ) a S 


3 


Sol.Prec. 




Residue. Solution. 


Ag 


Hg 




Eg Pb Bi Cd Cu 


As Sb Sn Au Pt 


a 

-t 

p 


| 




i?6S. 


Boil in HNO a . 
Sol. 


In H apparatus with Zn & H 3 S0 4 
Gas. Residue. 


1 

o 

3 


m 
p 


P 1 








Hg. 

►3 


Pb Bi Cd Cu 
With H 2 S0 4 . 


AsSb 
Pass into 
AgN0 3 


Sn Au Pt 
Boil in HCl. 






CD 
CO 

i. 


Free. Sol. 


Sol Res. 


Sol. Res. 


Pb 

3 


Bi Cd Cu 
NH 4 HO 


As 


Sb 
and 

Ag 


Sn 


AuPt 

HCl and 

HN0 3 . 










5t 


Free. Sol. 




CO 


&tf. 






Ct> 








3. 








Bi 


CdCu 


a 


P* 














KCy and^ 


*G 


w 


Au 


Pt 








3 


H a S 
Free. Sol. 


P 
pi 


a? 




9 








• 





















Cd. 


Cu 








Kj 


* 








H 


W 






2 












2L 


3 








3 










o 


p 

+ 






S 1 














*l 














o 














o 














^ 
































& 













QUALITATIVE ANALYSIS. 



287 



COMPLETE ANALYSIS. 



FILTRATE. 



Add H 3 S. 

FILTRATE 



Add NH* HO and (NH 4 ) a S. 







iVec. 












Filtrate. 






Co Ni Fe Cr Mn U Al Zn 


Add (NH 4 ) a CO s . 






Dilute HC1. 


Free. 


Filtrate. 


Ees. 


&tf. 








Fe Cr Mn U Al Zn 


Ba Sr Ca 
Dissolve in HC1. 




Co Ni. 


MgKNa 
2 Parts. 


►3 


Boil in Na HO. 


Add2HF, SiF 4 


EC 


Free. Sol. 


and alcohol. 
Free. Sol. 


7. 77. 








I2j 


Fe Cr Mn U 
(NH 4 ) a C0 3 . 


Al 
3 


Zn 






Ba 


SrCa 


Mg 




O 

o 


Ees. Sol. 


tr 




3 

St 


2 Parts. 
7. II. 


W 

o 
+ 

P 


^3 

Pg 

~p 
o p 


o* 


Fe Cr Mn 
Fuse with KN0 3 
andNa a C0 3 . Dis- 


u 


o 

s 

M 

a* 


Sr. 


Ca 

W 
1b 


p 
pi 


solve in H a O. 
Ees. Sol. 


s 

pi 

w 


P 






W 
o 
+ 
o 


g 
8" 


w 
p 


OS 
• P 

B 


9 








2§ 


Fe 


Cr 


Mn 


Q 








o 


p 
pi 

Pi 


p 


© 




GO 


4- 

3 


O 
o 












a 












cd 

P. 


p 


o 

s 

pi 










p 


p 

p 

CD 


























o 

3 





















288 



QUANTITATIVE ANALYSIS. 



S - 9 • • • 

ffl M 



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: :g 

to :W 

•W : + 

:o 

W 






tf 



fc&ft :fe 






ii 6 i ill 



a 



^ I 



2 



) 3.,o •:-« 



^1 



' b. an ,, ej „ «jj 









3 ^ -^ ^ 



^^5 

so 



+ I I ++ J I + + + I + 



+ + + +I++I l + l I + + + + + + 



I 



a a 

§1 



>» > 



gooKo 

I— It— I 



H^3 h h h K^hH £KEKH>-h 



» £ 

., HH M 

I— I H M *-< M M hHHujH V, H f 



02 



Mt-^ .00OO(J 
TfOrl .OOtDCJ 

T-imco • coio© k 



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«D fc- OS 00 ir- O i-< SO fl O CO 

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th «* ci os * t-^ ^' i-i j~ 



COOfc-;© IG <© 
t-h Or*Q0 CO CO 






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t-< O* <?* 00 <?* ,t-T-lriTHiH«W 

IMMMI II : IMMMMMMI 



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<N<Nt-COT^r-COT-iCOrfi-r-lOSCOiOlO«?CtT-(iH 



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r4 O 03 EJ 

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Q UALITA TIY E ANAL YSIS. 



289 



o 

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ft 

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CO «S 



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So? 



oo 



WW g 






° fV ° 

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OS, ? 



COoi -GSf .hu 



£ -o.S 



qj >*/ qj w j^. 

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Oi «D t- 00 T-frH COt-C0T*£-© CO OHOOM 

G* 00 C* <?* C? -r-l 23 t- C* CO CO «D tH tS t-( C* r-l C<i G* t-< «T-(rir(rl 

I I I 1 + I + I I i + + + I I I + + + I ! + I + + + 



. M M . M M Mp 



M>> O *"' H " 1 ** C &-• k_| t-L. I . 

^•^^OMq^O^O^OOM 
MHH MI-HM M I— II— I 



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5 gM oop- ^^'^'"'m 



"ir^s '^s^«s '^s^s 






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II : II : II ii 









© tJ4 T* OS «© CO tH t- OS ^ lfl -^l C5 00 00 CO t- <M CS C5 TF 00 00 O rP OHWWO 

1-1 T-» T-l TH TH T-l J-lrHWWH 1-1 T-l 



q^OOMMMWMWWcoco^^oQ^eHHEHencoH F t»<Nfcsl 




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CS "P © F* >" 

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5,2 33 IS *3 

03 03 g S ° 
2,d ©_ ^* 

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QUESTIONS FOR CLASS USE. 



I. — INTRODUCTION. 

Page 17. — Define chemistry. Illustrate. What is the distinction 
between organic and inorganic chemistry? Illustrate. What is an 
element? How many are known? Is it probable that all the ele- 
ments have been discovered? Define chemical affinity. Illustrate. 
How does it act? 

18. — How can we find what elements will combine ? What is a 
compound? Are compounds like their elements? Illustrate. 
What is the action of heat ? Of light ? Of solution ? Illustrate. 

19. — State the principles upon which the elements are named. 
Illustrate each. What are chemical symbols ? How are the sym- 
bols formed ? Define atomic weight. Illustrate. 

21. — State the four laws of the atomic theory. What is the molec- 
ular weight of a compound ? What is a binary compound ? Which 
element is placed first in reading the symbol of a compound ? In 
writing ? In reading the name ? Name the three variations from 
these rules. What is the use of the terminations -ide? -uret? De- 
fine an oxide. Define the different compounds of 0. 

22. — What is an acid? Must an acid always be sour ? Name 
one that is not (page no). What is the test? How does the ter- 
mination of an acid indicate its strength ? What is the meaning of 
the prefix per? — hypo? How are the hydracids named? 

23. — Define a base. An alkali. What is the reciprocal influence 
of the alkalies and the acids ? Define a salt. How is it named ? 
What is the difference between an -ous and an -ic salt ? What is 
a formula? 

24. — What signs are used ? To what is the proportion of an ele- 
ment in any compound always equal ? The weight of an element ? 
State the proportion to be used in solving problems. 



QUESTIONS FOE CLASS USE. 291 

II. — INORGANIC CHEMISTRY. 
1. — THE NON-METALS. 

Oxygen. — Give the symbol and atomic weight of oxygen. What 
is the meaning? What other element is an acid-former? 

28. — Name the sources of 0. Do these fractions indicate weight 
}r volume? How is prepared from potassium chlorate and 
manganese dioxide? Give the reaction. What becomes of the 
potassium chloride ? 

29. — What is the use of the black oxide of manganese? Define 
catalysis. Name the properties of 0. What is oxidation? An 
oxide? Show that is a supporter of combustion. What com- 
pounds are formed in these illustrations? What is an anhydride ? 
An acid ? 

31-32. — Describe the destructive effects of the in the air. What 
causes the decay of peaches? Why does not canned fruit decay? 
Describe the action of on fuel. On the teeth. On impure water. 
On writing-ink. On red-hot iron. On damp knives and forks. 
How is river-water purified on a sea-voyage ? 

33. — By what means is the carried through the system ? What 
work does it perform in the body ? Why is the blood in the arte- 
ries red and in the veins purple ? What chemical processes are 
included by the chemist under the term oxidation? 

3J/.. — Does fire differ from decay? Is heat always produced by 
oxidation? Illustrate. Describe the body as a furnace. 

35. — What is the chemical process of starvation? Why does 
unusual exercise cause one to breathe more rapidly? Why does 
running cause panting? Why do we need extra clothing when we 
sleep, even at midday, in the summer ? How do hibernating ani- 
mals illustrate this ? How does a cold-blooded animal differ from 
a warm-blooded one ? How does give us strength ? 

36. — How are action and reaction equal in chemistry as in phil- 
osophy ? What is potential force? Dynamic force? Show how 
is constantly burning the body. Is there any part of the body that 
is permanent? Illustrate the rapidity of this change. Show the 
truth of the paradox — " We live only as we die." 

37. — Why do we need food and sleep ? Show how acts as a 
scavenger in nature. In what sense is the sweeper of the body? 
Is this a useful provision ? 



292 QUESTIONS FOE CLASS USE. 

38. — How much does each adult need per day? Total amount 
used daily? What would be the result if the air were pure 0? 
What objects would escape combustion? What is ozone? Where 
is it seen ? 

39. — Preparation? Properties? Test? Is it a valuable constit- 
uent of the air ? What is antozone ? Its characteristic ? 

Nitrogen. — Symbol and atomic weight? Why so called? 
Sources ? Preparation ? 

J$. — Properties ? Why does a person drown in water ? Would 
a person die in pure N ? What is the peculiarity of the nitrogen 
compounds ? What causes flesh to decompose so much more easily 
than wood ? Does the N we take in at each breath do us any direct 
good or harm ? Where do we get N to make our flesh? 

43. — What use do plants make of the N they breathe in through 
their leaves? Describe the action of N and in our stoves. Where 
do plants obtain N ? State the main distinction between and N. 
What is the office of the N in the air ? Show that the proportion of 
and N in the atmosphere gives us the golden mean. 

44- — Symbol and molecular weight of nitric acid ? Common 
name ? Explain its occasional presence in the atmosphere. Prep- 
aration? Why is its symbol HNO :3 and not N 2 5 ? Show that in 
its salts an acid takes the place of the H. 

45. — Properties? Has it been obtained as a solid ? How does it 
rank in strength? What color does it give to wood? Uses? 
Explain its oxidizing action. What is aqua regia? Describe the 
process of etching. The action of HN0 3 on Sn. What are the red 
fumes which pass off? How does HN0 3 illustrate the power of 
chemical affinity? 

46. — Symbol and molecular weight of nitrous oxide ? The com- 
mon name? Preparation? Reaction? Properties? For what 
purpose has liquid nitrous oxide been used ? {Physics, page 191.) 
What is the effect of nitrous oxide on the human system ? State its 
use in surgical operations. Symbol and molecular weight of nitric 
oxide? Its preparation? Why is the gas in the jar colorless? 

' 47.— What compound is formed ? Properties of NO ? What are 
the fumes which it forms in the air ? Symbol and molecular weight 
of ammonia ? Why so called ? Its old name ? 

48.— What is aqua ammonia ? Whence obtained ? Give the reac- 
tion. Properties? 

49.— Prove that H 3 N is an alkali. What is its test ? Its antidote? 
How liquefied ? Define the nascent state. 



QUESTIONS FOB CLASS USE. 

Hydrogen. — Symbol and atomic weight ? Meaning of the name ? 
Preparation ? 

51. — Reaction ? What compound is formed ? Properties ? Is H 
a metal ? Ans. — In all reactions it plays the part of a metal, and 
like most of the metals is electro-positive. The size of its atoms ? 
Its levity ? Will it destroy life ? Effect on the voice ? Use in fill- 
ing balloons? 

52. — What is the product of the combustion of H ? What is the 
philosopher's lamp? What are the mixed gases? What is the 
cause of the report? Will the gases combine, if mixed ? Describe 
the hydrogen gun. 

54. — What compound is formed by the combustion of H ? What 
becomes of the H 2 0? What is the action of platinum sponge on a 
jet of H? What becomes of this force? Describe Dobereiner's 
lamp. Explain the heat produced by burning H. 

55. — How are hydrogen tones produced ? Explain. 

Water. — What is the freezing and the boiling point of water ? 
How is the composition of water proved ? Why does the black- 
smith sprinkle water on his forge fire ? 

57-8. — What injury may a small quantity of H 2 do, if thrown on 
afire? Explain. Can H 2 0, then, be burned? Show that electri- 
cal force is latent in water. What becomes of this force ? Illustrate 
the abundance of H 2 in the animal world. Vegetable world. 
Mineral world. 

59. — Why will blue vitriol lose its color if heated? What is 
" burnt alum? " Water of crystallization ? Show the adaptation of 
H 2 as a solvent. What water is the purest ? Why does rain-water 
taste so insipid ? 

60. — Is river water a healthy drink ? What is hard water ? Soft 
water ? Why does the hardness of water vary in different places ? 
Is hard water healthful ? How may we detect organic matter in 
H 2 0? What minerals are most common in water ? What is the 
"fur" in a tea-kettle? Why does soap curdle in hard water? 

61-2 . — What is the cause of the tonic influence of the sea-breeze ? 
How could Salt Lake be freshened ? What is the use of the air in 
H 2 0? How do fish breathe? Why does the air in water contain 
so much ? Why is boiled water so insipid ? Give some of the 
paradoxes of water. Name the various uses of water. {Physics, 
p. 201.) 

Carbon.-— Symbol and atomic weight ? Illustrate the abundance 



29Jf QUESTIONS FOR CLASS USE. 

of C. Is it more characteristic of the vegetable than of the mineral 
kingdom? What are its three forms? 

65. — Proof of these allotropic states? What is an allotropic con- 
dition? What is the diamond? Properties? Has it ever been 
made artificially? What is a carat? 

66. — How is the diamond ground ? Describe the three modes of 
cutting. What gives the diamond its value ? 

67. — Common name for graphite? Origin? Uses? Describe 
the process of making a lead-pencil. What is a black-lead cruci- 
ble? What is British Lustre? Gas carbon? How is charcoal 
made? 

68. — What is the chemical change ? Illustrate the durability of 
charcoal. 

69. — Its property of absorbing gases. Its preservative effects. 
Its filtering properties. (Physics, page 17.) What do you mean 
by the deoxidizing or reducing action of C ? Application to the 
arts? 

70. — What is soot ? What causes the burning of chimneys ? Does 
this occur oftener when wood than when coal is used as fuel ? How 
is lampblack made? Uses? Fitness for printing? What can you 
say about ancient MSS. ? How is boneblack made? Uses? How 
is sugar refined ? 

71. — Describe the formation of coal. Difference between bitu- 
minous and anthracite coal. Why is coal found in layers, with slate, 
etc., "between? Why is the coal hidden in the earth? What proof 
have we that coal is of vegetable origin ? 

72. — What is coke? Uses? Describe the formation of peat. 
Uses? What is muck? Use? Name some of the diverse proper- 
ties and uses of C. 

Carbonic Anhydride. — Symbol and molecular weight? 
Sources? How it is constantly formed ? 

74. — Preparation ? Reaction ? 

75. — Test ? What causes the pellicle on lime-water ? What does 
this show? Prove that we exhale C0. 2 . Give the properties of C0 2 . 

76. — Prove that C0 2 is heavier than air. A non-supporter of 
combustion, That it contains C. What test should be employed 
before descending into a deep well or an old cellar? How can you 
remove the foul air? 

77. — Tell about the Grotto del Cane. Is CCX directly poi- 
sonous? What is choke-damp? Fire-damp? Which is more 
dreaded ? 



QUESTIONS FOR CLASS USE. 295 

78. — Has C0 2 been used in extinguishing fires? Tell about the 
absorption of C0 2 by H,,0. What is soda-water? 

79. — How is C0. 2 liquefied ? Why does the liquid acid solidify 
when exposed to the air ? What principle in philosophy does this 
illustrate? How low a degree of cold has been produced in this 
manner ? Describe the need of ventilation. How is the air expired 
from our lungs made useful ? 

80. — Is a single opening sufficient to ventilate a room ? What 
practical application do you make of this subject? Symbol and 
molecular weight of carbonic oxide ? Properties ? 

81. — Where do we often see it? How is CO formed in a coal- 
fire ? Practical importance of this fact ? What causes the unpleas- 
ant odor of coal-gas? Symbol and molecular weight of light car- 
buretted hydrogen? Properties? How is it formed? 

82. — Name the places where it is found in great quantities. 
Symbol and molecular weight of heavy carburetted hydrogen ? 
Properties? 

83, — What gases mainly compose coal-gas ? Which is the most 
valuable? Describe the manufacture. Is the odor beneficial ? Is 
coal-gas explosive? Why is the jet flat? When we turn the gas 
very low, or the supply is insufficient, why is the flame blue ? Sym- 
bol and molecular weight of cyanogen? Meaning of the name? 

84. — Preparation ? What are its compounds called ? What is 
the ) r ellow prussiate of potash? The red? Ans. — The ferricyanide, 
K :3 FeCy 6 . Properties of Cy? What is a compound radical ? Sym- 
bol of hydrocyanic acid ? Common name ? Where found ? Anti- 
dote ? What are the fulminates? How are gun-caps made? 

Combustion. — Define. What is a combustible ? A supporter of 
combustion ? (The difference between these two is nicely shown in 
the experiment with H on p. 52.) A burnt body? Ans. — A body 
which has combined with 0. — Example : a stone, water. Upon 
what does the amount of heat produced by combustion depend ? 
The intensity ? W T hy do we need a draught to a stove ? What is 
meant by the igniting point of a substance ? Does combustion, in 
its chemical sense, commence before the fuel catches fire ? Why do 
we use "kindlings" in starting a fire ? Why can we light pitch- 
pine so easily ? What are hydrocarbons ? What are the ordinary 
products of combustion? What causes the dripping of stove- 
pipes? What are the ashes? Why does fresh fuel produce a 
flame? 

86. — Show how wisely C is adapted for a fuel. What would be 



296 QUESTIONS FOB CLASS USE. 

the effect if C0 2 were not a gas? Define flame. Describe the 
burning of a candle. 

87.— Show that flame is hollow. What causes the light ? Why is 
the flame blue at the bottom? Products of combustion ? Tests? 
Why does the wick turn black ? 

88. — What causes the coal at the end of the wick ? Why does 
snuffing brighten the light ? Why does a draft of air, or a sudden 
movement of the candle, cause a deposit of soot ? Why is the flame 
of a candle or lamp red, or yellow? Ans. — Because the heat is not 
sufficient to cause the carbon to emit all the rays of the spectrum. 
Use of plaited wicks ? Object of a chimney to a lamp ? 

89. — A flat wick ? Advantage of an Argand lamp ? What is the 
film which gathers on the chimney when the lamp is first lighted ? 
Why does this soon disappear? Why do tar, spirits of turpentine, 
etc., burn with much smoke ? Why does alcohol give much heat 
and no smoke ? Describe Davy's safety-lamp. Illustrate this by a 
wire gauze over the flame of a candle. 

90. — Describe Bunsen's burner. Why does it give great heat, 
little light, and no smoke? Describe the oxy-hydrogen blow-pipe. 

91. — Why does it give great heat and little light ? What is the 
calcium light ? 

92. — Describe the mouth blow-pipe. The three parts in the blow- 
pipe flame. What is the reducing flame ? 

93. — The oxidizing flame ? Why does blowing on a candle-flame 
extinguish it ? Why does water put out a fire ? Give illustrations 
of spontaneous combustion. 

The Atmosphere. — Name the constituents. Proportion. State 
the comparison. What is the law of diffusion? 

97. — What effect does this have on the air? Is the air a chemical 
compound? Illustrate. Has each constituent a special use? 
Name the uses of 0. Of C0 2 . 

98. — Explain the chemical change which takes place in the leaf. 
What force separates the C from the ? What is the influence of 
house-plants upon the atmosphere of a room ? What do you say of 
the exact balance kept between the wants of animals and plants ? 

100. — What relation exists between animals and plants ? Which 
gathers and which spends the solar force ? Which performs the 
office of reduction? Which that of oxidation? How is the solar 
force set free ? What is the use of the watery vapor in the air ? 

101. — Which of the constituents are permanent ? Is this o wise 



QUESTIONS FOR CLASS USE. 291 

provision ? Why ought the vapor to be easily changed to the liquid 
form ? What effect does this permanence have upon sound ? 

The Halogens. — Name them. Symbols and atomic weights. 
Compare the halogens with each other. What compounds do they 
form ? Why is chlorine so called ? Source ? 

103. — Preparation? Reaction? Properties? What. action does 
CI have on phosphorus, arsenic, etc. ? Why does a solution of the 
gas soon become acid ? What is its action on organic bodies ? On 
turpentine ? On printers' ink ? Describe the chemical change in 
domestic bleaching. 

104 — The method of bleaching on a large scale. What is the 
advantage of using CI over other disinfectants? How may the gas 
be set free ? 

105. — How are hospitals purified ? What mixture would liberate 
CI in the greatest quantities ? Symbol and molecular weight of 
hydiochloric acid? Common name? Preparation? Reaction? 
Properties ? What is muriatic acid ? What are its compounds 
termed? Tests? What is nitro-muriatic acid? 

106. — Symbol and molecular weight of chloride of lime ? Uses ? 
Symbol and molecular weight of calcium chloride ? Preparation ? 
Peculiar property ? Tell what you can about bromine. Its uses. 
What is the peculiarity of fluorine ? Source ? What acid does it 
form? For what is this acid noted? Describe the process of etch- 
ing with HF. 

107. — Why is not HF kept in ordinary bottles? Is it dangerous 
to use ? Why is iodine so called ? Preparation ? Properties ? 
For what are its compounds noted ? How may its stains be 
removed ? Test ? Use in medicine ? 

Boron. — Symbol and atomic weight ? Source ? Describe the 
scene in Tuscany where it is found. Process of manufacture. 

109. — Symbol and molecular weight of borax? Uses in solder- 
ing, and in softening hard water ? 

Silicon. — Symbol and atomic weight? Source? Common 
names ? What gems does it form ? What is sand ? Properties ? 

110. — Why is it called an acid ? Is silica soluble in H 2 ? How 
does it get into plants? In what plants is it found? Explain the 
process of petrifaction. What is said of the antiquity of glass? 
Pliny's story of its origin ? What is said of its value in the twelfth 
century? 

111. — Name the four varieties of glass and the composition of 
each. What are the essential ingredients of glass ? How is glass 



QUESTIONS FOR CLASS USE. 

colored ? Name the oxides used. Why is flint-glass so called ? 
How is glass annealed ? Describe the Prince Rupert's drop. 

112. — How are Venetian balls made ? Tubes ? Beads ? 

Sulphur. — Symbol and atomic weight ? Sources ? What is the 
principle of hair-dyes ? Why do eggs tarnish silver spoons ? What 
is the difference between brimstone and flowers of sulphur ? Prop- 
erties ? Solvent? Four allotropic forms? Describe the amor- 
phous state. 

114> — Uses of S ? Symbol and molecular weight of sulphurous 
anhydride ? Where is it familiar ? What are its compounds called ? 
Uses in bleaching? Why are new flannels liable to turn yellow 
when washed ? Symbol and molecular weight of sulphuric anhy- 
dride? By what other name is it known? Preparation ? Prop- 
erties ? Why is Nordhausen acid so called ? 

115-16. — Symbol and molecular weight of sulphuric acid ? Com- 
mon name? State its importance. What are its compounds 
called? Illustrate the making of H 2 S0 4 . Describe its manufacture. 
Reaction. 

117. — Properties? What especial property? Illustrate. Its 
strength ? Color of its stain on cloth ? How removed ? On wood ? 
Cause of this action? Test? Symbol and molecular weight of hy- 
drogen sulphide ? Where is it found ? 

118. — Preparation ? Reaction ? Properties ? Use ? Color of 
these precipitates ? Test ? Symbol and molecular weight of carbon 
sulphide ? Preparation ? Properties ? Uses ? How does it illus- 
trate the force of chemical affinity? 

Phosphorus. — Symbol and atomic weight ? Why so called ? 

120. — Source ? In what parts of the body, and in what forms, is 
it found ? Preparation? Properties? Caution to be observed? 
Is phosphorus poisonous? What is the product of its combus- 
tion? 

121. — Describe the amorphous form of phosphorus. What is the 
principal use of phosphorus ? Describe the making of the lucifer 
match. The safety match. What compounds are formed in the 
burning of a match ? 

122. — What is phosphorescence ? Its cause ? Symbol and molec- 
ular weight of hydrogen phosphide? Source? Preparation? 
Properties ? 

Arsenic. — Symbol and atomic weight ? Common name ? Test ? 
What is commonly sold as arsenic or ratsbane? Preparation of 
arsenious acid ? Properties ? What can you tell of its antiseptic 



QUESTIONS FOR CLASS USE. 299 

property? Antidotes? Describe Marsh's test. How can the As 
be distinguished from Sb?* What is said of arsenic eating? 

2. — THE METALS. 

Potassium.— Symbol and atomic weight? History of its discov- 
ery? Source? How do we get our supply ? Preparation? 

127. — Properties ? How must it be kept? Reaction when thrown 
on H 2 0? Symbol and molecular weight of potash? Of potassium 
hydrate? Properties? Its feel? Its affinity for H 2 and C0 2 ? 
Uses? Symbol and molecular weight of potassium carbonate? 
Common name? 

128. — Preparation ? What part of the tree furnishes the most 
potash? What is the derivation of the word? Symbol and molec- 
ular weight of hydrogen potassium carbonate? Common names? 
Preparation? Define a rational formula. Illustrate. An empirical 
formula? Illustrate. What is a neutral salt? An acid salt? A 
dibasic acid ? 

129. — Symbol and molecular weight of potassium nitrate ? Com- 
mon names? Where is it found ? How is it prepared artificially? 
How much water would be required to dissolve a pound of this 
salt? Properties? Uses? What is the composition of gunpowder ? 
Cause of its explosive force? 

130. — Uses of potassium chlorate? Potassium bichromate? 
Composition of fire-works? 

Sodium.— -Symbol and atomic weight ? Source? What propor- 
tion does it form of common salt ? What element does it resemble ? 

131. — Reaction when thrown on water? What compound is 
formed ? Test ? Symbol and molecular weight of common salt ? 
What use does it subserve in the body? Is salt abundant? De- 
scribe the manufacture. 

132. — What is solar salt ? Describe the " hopper-shape " crystal. 
Is it best to heat the water for dissolving salt ? What is a saturated 
solution? 

133. — Symbol and molecular weight of sodium sulphate ? Com- 
mon name ? Preparation ? Reaction ? What curious property has 
this salt? Why will the dropping in of a crystal cause solidification ? 

* Antimony is more likely to be mistaken for arsenic than for any other metal. 
The crust which is formed by decomposing - antimoniuretted hydrogen in Marsh's 
apparatus does not yield octahedra, when sublimed in a tube with air, but 
prisms. The metal is also easily soluble in yellow ammonium sulphide, which is 
nearly without effect upon arsenical crusts.— Miller. 



300 QUESTIONS FOR CLASS USE. 

Symbol and molecular weight of sodium carbonate? Common 
names ? Why called carbonate of soda ? 

134- — Describe its manufacture. Why will Na. 2 S0 4 soften hard 
water? Symbol and molecular weight of hydrogen sodium carbon- 
ate? Common name? Why called bicarbonate of soda? Prepara- 
tion? Use? What is an empirical formula? A rational formula? 
Give the theory of ammonium. How is the symbol H 4 N,HO ob- 
tained ? What is a compound radical ? A compound halogen ? 

135. — Symbol and molecular weight of ammonium chloride? 
Preparation? Uses? Symbol and molecular weight of ammonium 
carbonate? Common names? Uses? Symbol and molecular 
weight of ammonium nitrate ? Preparation ? Uses ? What is the 
sodium amalgam ? 

Calcium. — Symbol and atomic weight ? Source? In what part 
of the body is it found? In what form do we commonly see it? 
Symbol and molecular weight of lime? Preparation? Describe a 
lime-kiln. Properties of CaO? Test? 

137. — What is the difference between " water-slacked " and " air- 
slacked" lime? Uses? What is whitewash? Concrete? Hard- 
finish? Calcimining? Theory of the hardening of mortar ? Why 
are newly-plastered walls so damp? Will mortar harden if pro- 
tected from the air? Action of lime on the soil ? Will it not lose 
its beneficial effect after a time ? Should it be applied to a compost 
heap? How can this waste be avoided? How would you test for 
the escaping H 3 N ? Action of lime on copperas? How does the 
copperas get in the soil ? 

138. — Uses of lime ? Symbol and molecular weight of carbonate 
of lime? Source? How are stalactites and stalagmites formed? 

139.— What is petrified moss? Whiting? Marble? Chalk? 
Marl ? Symbol and molecular weight of calcium sulphate ? Com- 
mon names ? What is plaster of Paris ? Why does plaster of Paris 
harden, if moistened ? Ans. — Because it absorbs water again. 
Uses? W T hat is plaster? How prepared for use as a fertilizer ? 
Ans. — It is ground into a fine powder. Tell the story of Franklin. 

lJ/O. — What is the difference between sulphate and sulphite of 
lime ? Symbol and molecular weight of phosphate of lime ? What 
is the superphosphate? Use? Uses of the salts of barium and 
strontium ? What is heavy spar ? Barytes ? 

Magnesium. — Symbol and atomic weight? Source? How can 
you tell if a stone contains Mg? Ans, — It generally has a soapy 
feel. Properties ? For what is it noted? Name the two classes of 



QUESTIONS FOR CLASS USE. SOI 

rays contained especially in its light (Physics, page i63). For what 
purposes do the colorific rays adapt it? Does it contain heat-rays 
also? Ans. — Very few. Product of its combustion? Symbol and 
molecular weight of magnesium carbonate ? Magnesium sulphate ? 
Common name ? 

Aluminum. — Symbol and atomic weight ? Common name ? 
Source? Properties? Solvent? What can you say of its abund- 
ance and probable usefulness? What is alumina ? What crystals 
and gems does it form ? What is emery? Symbol and molecular 
weight of silicate of alumina? Common name ? Source ? 

144- — Use in the soil? In the arts? What is ochre? Fuller's 
earth ? Explain the process of glazing pottery ware. What is the 
salt glaze? The litharge glaze? What objection to the latter? 
What gives color to brick ? What is the peculiarity of white brick ? 
How is alum made ? 

145. — Name the different kinds of alum. Which kind is the com- 
mon commercial alum ? Use of alum in dyeing ? How are alum 
crystals maple? Ans. — They are obtained by suspending threads in 
a saturated solution of this salt. In this manner alum baskets, 
bouquets, etc., are formed of any desired color. What is spectrum 
analysis? Is it a reliable test? Illustrate its delicacy? What is 
the spectroscope ? 

Iron. — Symbol and atomic weight ? Tell what you can of its 
value to the world. How is its use a symbol of a nation's pro- 
gress ? 

149. — State how its value is enhanced by labor. Name the 
sources of iron. Common ores. Describe the process of smelting 
iron ore. Why is hot air used for the blast? Reaction of the 
lime? 

151. — What becomes of the in the ore ? Origin of the term 
" pig-iron? " Name the varieties of iron. Difference between them. 
What is cast-iron ? Its properties? Uses? What exception adapts 
iron for use in castings ? What does this teach us ? What is chilled 
iron? Wrought iron? 

152. — Preparation? Effect of jarring? How is Fe tempered? 
Illustrate its malleability. What is steel ? Preparation ? In mak- 
ing steel tools, how does the workman judge of the temper? How 
are cheap knives made ? 

153. — Describe Bessemer's process. Cause of the changing col- 
ors often seen in the scum over standing water ? 

154. — Name the different oxides of iron. Give the symbol of 



$02 



QUESTIONS FOR CLASS USE. 



each. Where is each found ? Origin of colored sand ? What 
peculiar property is possessed by the ferric oxide and ferric hy- 
drate ? What is iron carbonate ? By what name is it known ? 

155. — Cause of the ferruginous deposit around chalybeate 
springs ? Symbol and molecular weight of iron bisulphide ? Com- 
mon names? Of ferrous sulphate? Preparation? Uses? What 
is chameleon mineral ? 

Zinc. — Symbol and atomic weight? Source? Preparation? 
Reaction? Is it malleable? Will it oxidize in the air? Uses? 
What is philosopher's wool? What is galvanized iron? Are water- 
pipes made of this material safe ? Symbol and molecular weight of 
zinc oxide? Use ? Symbol and molecular weight of zinc sulphate? 
Use? 

Tin. — Symbol and atomic weight ? Where found ? Properties ? 
What is the "tin cry?" What is common tin-ware? Action of 
HNO :} on Sn ? What can you say of the manufacture of pins ? 

Copper. — Symbol and atomic weight ? Where found? Antiquity 
of the mines ? What is malachite ? Properties of Cu ? Color of 
its vapor? How tempered ? Test? What is verdigris? Carbon- 
ate of copper? Black oxide of copper? What is the danger of 
using a copper kettle? Solvent of Cu? Test? Symbol and molec- 
ular weight of copper sulphate ? Common name ? Uses ? 

Lead. — Symbol and atomic weight? Source? Preparation? 
Properties ? Its effect on the human system ? On water ? Is there 
more danger with hard, or with soft water? What precaution 
should always be used with lead pipes? What is the test of lead? 
What is " litharge ? " Its uses ? " Red-lead ? " Its uses ? What is 
" white-lead ? " Describe its manufacture. With what is it adul- 
terated ? What is "sugar of lead?" Properties? Antidote? 
Explain the formation of the lead-tree. 

Gold. — Symbol and atomic weight? Source? Preparation? 
What is an amalgam ? Quartation ? Properties? Solvent? Pro- 
cess of making gold-leaf? 

Silver. — Symbol and atomic weight ? Source ? Preparation, i, 
from the sulphide ; 2, horn-silver ; 3, lead? Describe the process 
of reduction at the West. What is cupellation ? Properties ? Sol- 
vent? Test? What is the common name of nitrate of silver? 
What is its action on the flesh? How may its stain be removed? 
Uses ? Of what are hair-dyes and indelible inks made ? Describe 
the process of Daguerreotyping. Photography. 

Platinum. — Symbol and atomic weight ? Source ? Preparation ? 



QUESTIONS FOR CLASS USE. 

Properties? Uses? Why is iridium so named? What is iridos- 
mine ? How is platinum wire made? 

Mercury. — Symbol and atomic weight ? Common name ? Why 
so called ? Source? Preparation? Properties? Uses? Action 
on the human system ? Process of silvering mirrors ? What is 
blue-pill ? Mercurial ointment ? Symbol of mercuric oxide ? Mer- 
curous chloride? Mercuric chloride? Common name? Uses? 
Properties ? 

The Alloys. — What is an alloy ? What peculiarity with regard 
to the melting point ? Of what is type-metal made ? Pewter ? 
Britannia ? Brass ? German silver ? Solder ? Fusible metal ? 
Bronze? How is gold soldered ? Silver? Copper? What is the 
principle? What are the constituents of gold coin? Silver coin? 
What is the meaning of the term carat ? How are shot manufac- 
tured ? How are they sorted ? What is oreide ? Aluminum 
bronze ? Compare the properties of the metals with regard to, i, 
oxidation ; 2, density ; 3, melting point ; 4, color ; 5, malleability ; 
6, brittleness ; 7, tenacity ; 8, special properties. 

III. — ORGANIC CHEMISTRY. 

Introduction. — Why must matter be organized ? What is the 
office of plants ? 

182, — What is the difference between organic and inorganic 
bodies ? Illustrate each of the four distinctions. 

183. — What is the number of carbon compounds ? Define isomer- 
ism. Illustrate. What is the cause ? Allotropism ? Illustrate. 

Starch. — Symbol and molecular weight? Sources ? Use in the 
plant ? Why stored in that form ? Appearance under the micro- 
scope ? Preparation? Properties? What is dextrine? Test of 
starch ? Varieties ? What is gum ? Composition ? Mucilage ? 
Is it soluble in water ? What is pectose ? Pectin ? 

Woody Fibre. — Symbol and molecular weight ? What is the 
composition of wood ? Name the various forms of cellulin. Illus- 
trate the wonders of secretion. State the uses of woody fibre. The 
making of paper. Paper-parchment. Linen. Cotton. Gun-cotton 
[C 6 H 7 (N0 2 ) : ,0 5 ]. Collodion. Its uses. Cane-sugar. How is 
sugar refined? Difference between loaf and granulated sugar? 
Describe a centrifugal machine. What is terra alba ? Use ? Of 
what are gum drops made ? Rock-candy ? What is caramel ? 
Use ? Symbol and molecular weight of grape-sugar ? Source ? 



804 QUESTIONS FOB CLASS USE. 

Sweetening power? How is sugar made from starch? How does 
the oil of vitriol act? How do jellies, preserves, etc., " candy?" 
Why are dextrose and levulose so named ? 

Fermentation. — Cause ? Does it ever take place spontane- 
ously? How does the yeast act? What change takes place in the 
alcoholic fermentation? The acetic? Describe the formation of 
yeast. The making of malt. Yeast cakes. The varieties of fer- 
mentation. What is gluten ? How does it act ? What is diastase? 
Describe the brewing of beer. Why is lager beer so called ? De- 
scribe the making of wine. What is the difference between a dry, 
a sweet, and an effervescing wine ? Cause of the flavor ? State the 
proportion of alcohol in common liquors. How is brandy made? 
Rum? Whisky? Gin? Describe the apparatus used for distilla- 
tion. Symbol and molecular weight of alcohol ? What is said of its 
affinity for water ? What is absolute alcohol ? Name the uses of 
alcohol in the arts. Effects of alcohol on the human system. Sym- 
bol and molecular weight of ether? Is it properly called sulphuric 
ether? (See p. 203.) Preparation? Properties? Uses? Prep- 
aration of chloroform ? Properties ? Uses ? What is chloral ? 
Chloral hydrate ? Properties ? Uses ? Symbol and molecular 
weight of acetic acid ? What is the glacial acid ? Preparation of 
vinegar? What causes the working of cider ? What change takes 
place ? Properties of acetic acid ? Use ? What causes the " work- 
ing " of preserves ? What is aldehyde ? 

Organic Radicals — What is a radical ? A homologous series? 
Name the terms of the marsh-gas series. What is ethyl, methyl, 
etc. ? By what other name is marsh-gas known ? Describe the 
formation of the alcohols. By what other name is common alcohol 
known? State the formation of the aldehydes and acids. The 
ethers? The compound ammonias. The salts of the radicals. 
Uses. 

Destructive Distillation. — What change takes place in the 
decay of wood ? Effect upon the soil ? What change takes place 
in the distillation of wood ? Why is it called " destructive ? " 
What is pyroligneous acid ? Use? Creosote? Properties? Uses? 
Paraffine? Properties? Uses? How is tar made ? What are the 
products of the distillation of coal-tar ? Properties of carbolic acid ? 
What are the picrates ? Uses ? What is benzole ? Benzine ? 
Properties ? Uses ? What is phenyl alcohol ? What is nitro-ben- 
zole ? What are the coal-dyes ? Give an account of their discovery 
and properties. What is naphtha? Naphthaline? Anthracene? 



QUESTIONS FOB CLASS USB. 805 

Alizarin? Dead-oil? Uses? Petroleum? How formed? De- 
scribe its distillation. The rectification of kerosene. Danger of 
kerosene explosions. The test given by Dr. Nichols. How is bitu- 
men formed ? Describe Tar Lake. What is " Greek fire ? " 

The Organic Acids. — Where is oxalic acid found ? Prepara- 
tion? Properties? Antidote? Uses? Where is tartaric acid 
found ? Preparation ? What is cream of tartar ? Tartar emetic ? 
Rochelle salt ? Seidlitz powders ? Where is malic acid found ? 
Citric? Tannic? Name its varieties. What are nut-galls ? Prop- 
erties of tannin ? Describe the process of tanning. How is leather 
blackened? How is ink made? Why does writing-fluid darken 
by exposure to the air? What is gallic acid ? Pyrogallic ? Use? 

The Organic Bases. — Sources? What is opium? Preparation? 
Uses ? Laudanum ? Paregoric ? Danger of opium-eating ? What 
is morphine ? Use ? Quinine ? Use ? Nicotine ? Properties ? 
Strychnine? Properties? The chromatic test? Name the active 
principle of tea and coffee. What substances are found in tea? In 
coffee? Describe the process of tea-raising. Of making black tea. 
Green tea. 

Organic Coloring Principles. — Source? What is an adjective 
color ? A substantive color ? A mordant ? The process of dyeing ? 
Of calico printing? What is madder? Its coloring principle? 
Cochineal? Use? Brazil-wood? Use? Indigo? Preparation? 
White indigo ? Logwood ? Litmus ? Leaf-green ? 

Oils and Fats. — Name the two classes. What is the difference 
between them? What is the composition of the fatty bodies? 
Illustrate. What is glycerin ? Uses ? Nitro-glycerin ? Illustrate 
the formation of soap. What is the reaction ? Difference between 
hard and soft soap? What is the cause of the curdling of soap in 
hard water ? Describe the cleansing action of soap. What is sapon- 
ification? How is stearin made? What are adamantine candles ? 
Is wax of animal or vegetable origin? How is it bleached ? What 
is a drying oil? Boiled oil? Putty? Printers' ink? Cod-liver 
oil? Crotonoil? Castor oil? Sweet oil? Uses? Sources of the 
volatile oils ? Preparation? Composition? Name the three 
classes. Illustrate each. What is oil of turpentine? Rosin? 
Camphene? Camphor? Preparation? Properties? 

Resins and Balsams. — What is the difference between a resin 
and a balsam ? Illustrate. Source? Properties? Uses? What 
is rosin ? Preparation ? Uses ? Lac ? Source ? Preparation ? 
Shellac? Sealing-wax? Gum Benzoin ? Uses? Amber? Origin? 



306 QUESTIONS FOR CLASS USE. 

Properties? Uses? India-rubber? Source? Properties? Uses? 
What is vulcanized rubber? Properties? Gutta-percha? Uses? 

Albuminous Bodies.* — Name them. What' is their composi- 
tion? What is albumen ? Source? Properties? Casein? Why 
does milk curdle? Action of rennet? Why does cream rise on 
milk? Describe the souring of milk. What is gelatin? Glue? 
Isinglass? Size? Fibrin? Properties? Gluten? Legumin ? 
Putrefaction ? Cause ? Why does salt preserve meat ? 

Domestic Chemistry. — Describe the chemical changes which 
take place in making bread. What is stale bread? Why is it dry? 
How is aerated bread made ? Why is bread ever sour ? How are 
griddle-cakes raised ? Biscuit? What are baking-powders? Ac- 
tion of soda and HCI ? Of sal -volatile ? How is bread changed by 
toasting? How are potatoes changed by cooking? 

* Notice here the wise provision of nature. Nitrogen, slow and sluggish when 
uncombined, is fitted to dilute the air ; while N, restless and uneasy when com- 
bined, is equally adapted to form unstable compounds of food, to carry force 
into our bodies and there to quickly set it free. Oxygen, when free, is active, 
eager, and ready to search the nooks and crannies of the capillaries ; but when 
once it combines with a substance, takes it for better or for worse, and forms the 
stablest of compounds. We find nitrogen compounds in the animal and vegeta- 
ble worlds, ready for use where they are needed, in our muscles. Oxygen com- 
pounds are abundant in the mineral world, and stored in the seeds of plants, at 
hand to give form to the more permanent parts of the body. Such profound 
relations, such nice adaptations of our bodies to the world around, give us 
glimpses of a creative skill worthy our Hoblest thought and highest admiration. 



J H S % 7 • 



This Index includes the Notes as well as the Text. 



PAGE 

Acid Acetic 198 

M Arsenious 103 

11 Benzoic 220 

M Boracic 108 

11 Carbolic 206 

" Carbonic 78 

41 Chaomic 130 

44 Cicric 211 

44 Formic 202 

44 Fulminic 84 

44 Gallic 212 

44 Hydrochloric . . 105 
44 Hydrocyanic... 84 
44 Hydrofluoric... 106 
44 Hydrosulphuric 117 

44 Lactic 193, 230 

44 Malic 211 

44 Muriatic 105 

44 Nitric 44 

44 Oleic 218 

44 Oxalic 210 

44 Palmitic 218 

44 Phosphoric 31 

44 Picric 206 

44 Prussic 84 

44 Pyrogallic 212 

44 Pyrofigneous . 205 

44 Silicic 109 

44 Stearic 218 

44 Sulphuric ...... 115 

44 Sulphurous 114 

44 Sulphydric 117 

44 Tannic 211 

41 Tartaric 210 

Acids 22 

44 Vegetable 210 

Air 96 

Albumen 228 

Alcohol 196 

44 Definition of. 202 

44 Methyl 201 

44 Phenyl 206 

Alcohols, The 201 

Aldehyde 199,201 

Alizarin 208 

Alkalies 23 



PAGE 
. . 212 



i Alkaloids 

j Allotropism 183 

! Alloys/ 172 

Alum 144 

Alumina 143 

Aluminum 143 

44 Bronze... 174 

44 Silicate... 143 

Amalgam 163 

Amber 226 

Ammonium 134 

Ammonium Car-/ 

bonate j" I35 

Ammonium Chloride 135 

44 Nitrate.. 135 

Ammonia 47 

Amyl 200 

44 Acetate 204 

44 Valerianate 204 

Anhydride 29 

■ Arsenious 124 

44 Nitric 44 

14 Sulphuric 114 

Aniline 207 

Animal charcoal 70 

Anthracene 208 

Antimony 173 

Antozone 40 

A qua-ammonia 48 

Aqua-fortis 45 

Aqua-regia 105 

Arsenic 123 

Arseniuretted hy-l TO _ 

drogen f I2 ° 

Asphaltum 209 

Asphyxia 76 

Atomic theory 21 

kl weight 19 

Atmosphere 96 

Atmosphere, Per- ) 

manence of f IQI 

Balsams 225 

Barium 140 

44 Chloride 140 

Barytes 140 



PAGE 

Bases 22 

Beer 194 

Bees-wax 221 

Benzole (benzine) 206 

Bessemer's process.. 153 

Binary compounds. . 21 

Bismuth 173 

Bitumen. . . - 209 

Blast-iurnace 150 

Bleaching 103 

Bieaching-powder. . . 106 

Blow-pipe 92 

blow-pipe, Oxy-/ 

hydrogen j y 

Bones 230 

Bone-black 70 

Borax 109 

Boron ic8 

Brass 173 

Bread 232 

Brick 154 

Brimstone 113 

Britannia- ware 173 

Bromine 106 

Bronze 174 

Bunsen's burner 90 

Burning-fluid 224 

Butter 229 

Caffeine 211,215 

Calcimine 137 

Calcium 136 

44 Carbonate... 138 

44 Chloride 106 

44 Hypochlorite 106 

44 -Light 90 

44 Oxide 136 

44 Phosphate . . 140 

44 Sulphate 139 

44 Sulphite 140 

Calico-printing 216 

Calomel 172 

Camphene 224 

Camphor 224 

Candles 221 

Caoutchouc 227 



810 



INDEX. 



PAGE 

Cara f 65,174 

Caramel 191 

Carbon 64 

4 Disulphide. . . 118 

Carbonic Acid 30,78 

u Anhydride. 73 

" Oxide 77,80 

Carburetted hy - { Qr a „ 

dro/en ...f 8x ' 8a 

Carmine 217 

Case-hardening 152 

Casein 229 

Cast-iron 151 

Catalysis 29 

Cells 186 

Cellulin 186 

Chalk 138 

Charcoal 6j 

Cheese 229 

Chemicai affinity 17 

Chemistry, Organic. 179 
44 of candle. 86 

41 " lamp.. 83 

" " fire 83 

14 Domestic 232 

Chilled iron 151 

Chlorine 102 

Chloroform 198 

Chloral, Hydrate of.. 198 

Choke-damp 77 

Chrome yellow 130 

Chromium 130 

Cinnabar 170 

Cider 198 

Clay . 143 

Coal 71 

44 -gas 82 

44 -oil 208 

44 -tar 206 

Cobalt 123 

Cochineal 217 

Coin 174 

Coke 72 

Collodion 190 

Compound Ammo- ) 

nias ) 3 

Compound Blow- I 

pipe f 9 ° 

Compound Ethers. . . 204 
^ 4 Radical.. 84 

Combustion 33*85 

Concrete 137 

Confectionery 191 

Copper 158 

u Acetate 159 

44 Carbonate... 159 

44 Oxide 159 

44 Sulphate 159 

Copperas 155 

Coral 138 

Corrosive sublimate. 172 

Cotton 189 

Cream 239 

Cream of tartar 210 

Creosote 205 



PAGE 

Cupellation 165 

Cyanogen 83 

Daguerreotype 167 

Davy's Safety Lamp . 89 

Decay 204 

Dextrine 185 

Dextrose 191 

Diamond 65 

Diastase 194 

Diffusion, Law of 97 

Disinfectant 106 

Distillation 196 

Distillation, De - { 

structive j 4 

Drummond Light 91 

Dyads 139 

Dyeing 216 

Efflorescence 59 

Elements 17 

14 Symbols of 19 
Empirical formula ... 128 

Essences 223 

Etching 45 

Ether 197 

Ethers, The 202 

44 Compound.. 204 

Ethyl 200 

44 Butyrate 204 

44 Hydrate 201 

44 Hydride 200 

44 Oxide 202 

Fats 218 

Fermentation 192 

Ferric Disulphide 155 

F< nous Sulphate 155 

Fibrin 230 

Fire-damp yj 

Fire-works 130 

Fish, Breathing of... 61 

Flame 85 

Fluorine 106 

Force, Correlation of 35 

Formula, Empirical.127-8 

44 Rational... 128 

Fulminates 84 

Fusil oil 201 

Fusible metal 173 

Galena 159 

Galvanized iron 156 

Gas, Carbon. 67 

44 Illuminating ... 82 
44 Diffusion of.... 97 

44 Olefiant 82 

Gelatin 230 

German silver 173 

Glass no 

Glazing of pottery- j 

ware j" x *4 

Gluten 194 

Glue 230 

Glycerin 219 



PAGE 

Gold 162 

Graphite 67 

Gum 186 

' 44 Arabic 186 

44 Benzoin 226 

44 Lac 226 

Gun-cotton 189 

Gunpowder 129 

Gutta-percha 228 

Gypsum 139 

Halogens 102 

Hartshorn 47 

Heat 18,33 

Hematite 154 

Homologous bodies. 200 

Humus 204 

Hydrates 30,58 

Hydraulic cement . . . 137 

Hydrocarbons 85 

Hydrogen 50 

Hydrogen sodium j. 

carbonate f 3 * 

Hydrogen sulphide. 117 

Hydrogen, Heavy ) « 

carburetted — f 

Hydrogen, Light I g 

carburetted f 

Hydrogen phos- j 

phide J I22 

Hydrogen potas- ) g 

sium carbonate ) 

Hydrogen tones 55 

India-rubber 227 

Indigo 217 

Ink. 212 

44 Printers' 103 

Iodine 107 

Iridium 169 

Iron 148 

44 Carbonate 154 

44 Disulphide .... 155 

44 Oxide 154 

44 Sulphate 155 

44 Sulphuret 265 

Isomerism 183 

Ivory-black 65 

Kerosene 208 

Lampblack 70 

Laudanum 213 

Laughing-gas 46 

Lead 159 

44 Acetate 161 

44 Black 67 

44 Carbonate 161 

44 Dioxide 161 

44 Red 161 

44 Sugar of 161 

44 Tree 161 

44 White..... 161 

Leather . . ., 2ix 

Light 18 



INDEX. 



811 



PAGE 

Lignine 186 

Lime 136 

44 Carbonate of. . . 13S 

u Chloride or. 106 

44 Sulphate of. 139 

41 Phosphate of. .. 140 

Lime, Superphos - \ Tjn 

phate of J I4 ° 

Lime-Light 91 

Limestone 138 

Linen 189 

Litmus 22,217 

Litharge 161 

Logwood 217 

Lunar caustic ... 167 

Lye 128 

Madder 217 

Magenta 207 

Magnesium 141 

44 Carbonate 141 

44 Citrate 211 

44 Sulphate.. 142 

Malleable iron 151 

Malt 193 

Manganese 155 

Marble 138 

Marl 138 

Marsh-gas Si 

Marsh-gas series .... 200 

Marsh's test 124 

Matches - • 121 

Mathematics of ) 

chemistry J 4 

Mauvre 207 

Mercury 170 

44 Chloride 171 

Metals 126 

44 Alkalies 126 

Metals, Alkaline ) * 

earths f *3 6 

Metals, Earths 143 

44 Noble 162 

44 Useful 148 

Methyl 200 

44 Alcohol 201 

Methylated spirit 201 

Milk 239 

Mirrors 171 

Mixed gases 52 

Molasses 190 

Monads 139 

Mordant 145 

Morphine 214 

Mortar 137 

Muck 72 

Musical tones 55 

Naphtha 208 

Napthaline 208 

Nascent state 49 

Nickel 173 

Nicotine 214 

Nitre 129 

Nitric oxide 46 

Nitrous oxide 46 



PAGE 

Nitrogen 41 

Nomenclature 19 

Nordhausen sul - | 

phuric acid f * 

Oil, Bitter almonds. . 206 

44 Castor 222 

14 Fusil 201 

44 Kerosene 208 

44 Lemon 223 

44 Linseed 221 

44 Olive 222 

44 Turpentine 224-5 

44 of vitriol 115 

Oils 218 

Olefiant gas 82 

Olein 218 

Opium 213 

Oreide 175 

Organic acids 210 

44 bases 212 

44 chemistry.. 180 
Organic coloring I , 

principles ) 

Organic radicals. . .84,200 

0rg m^°. n ....° f | l8 ° 

Osmium 169 

Oxygen 27 

Oxy-hydrogen) 

blow-pipe ) y 

Ozone 38 

Paper 188 

Paraffine 205 

Parchment 189 

Paregoric 213 

Pearlash 128 

Peat 72 

Pectin 186 

Pencils 67 

Percussion caps 84 

Permanence of at- I 

mosphere j 

Peruvian bark 214 

Petrifactions no 

Petroleum 208 

Pewter 173 

Phosphate, Acid \ 

calcium J 34 

Phos r horescence 122 

Phosphorus 119 

Phosphuretted hy- ) 

drogen j I22 

PhotograDhy 167 

Picrates, The 206 

Pitch 224-5 

Plants in the room. . 98 
Plants, Office of. .100,181 

Plaster of Paris 139 

Plastering 137 

Platinum 169 

Plumbago 67 

Potash, (Potassa) .. 127 

44 Bicarbon- I 

ate of... f I28 



PAGE 

Potash, Bichromate / 

of f x 3° 

44 Carbonate of 127 
44 Chlorate ot.. 130 
44 Nitrate of . . . 129 
44 Picrate of . . • 206 
44 Prussiate of84,257 

Potassium 126 

Pottery 144 

Practical Questions. . 40 
49,63,94,118,146,176,236 

Preserves 192,199 

Problems 24 

Prussic acid 84 

Putrefaction 231 

Pyroxylin 189 

Quart ation 163 

Quartz 109 

Quicksilver 170 

Quinine 214 

Radicals 84,200 

11 Salts of 203 

Red precipitate 172 

Rennet 229 

Resin 225 

Rochelle salt 211 

Rosaniline 207 

Rosin 225 

Sago 185 

Sal-ammoniac 135 

Saleratus 128 

Sal-soda 133 

Salt, Common 131 

44 Epsom 142 

44 Glauber's 133 

44 Rochelle 211 

Salt of tartar (sal- ) _„ 

soda) ....[ J 33 

Salts 22 

44 of the radicals.. 203 

44 of lemon 210 

Salted meat 232 

Saltpetre 129 

Sal-volatile 135 

Sand 109 

Secretion 187 

Seidlitz powders 210 

Shellac 226 

Shot 174 

Silicon 109 

Silica no 

Silicates no 

Silver 164 

44 Chloride 167 

44 Nitrate 167 

Smelting 149 

Soap 218 

Soda, Bicarbonate of. 134 
44 Carbonate of. . 133 

44 Sulphate of 133 

Sodium 130 

44 Amalgam 134 

44 Caibonate... 133 



$is 



INDEX. 



PAGE 

Sodium, Chloride of. 131 

" Sulphate ... 133 

Solar force 100 

Solder 173 

Solution 18 

Soot 70 

Spectrum analysis. . . 145 

Spelter 156 

Spongy platinum ... 54 
Spontaneous com- ) 

bustion j 93 

Stalactites 138 

Stalagmites 139 

Starch 184 

Stearin 218 

Steel 152 

Strontium 140 

Strychnine 214 

Sublimation , . 107 

Sucrose 190 

Sugar, Cane 190 

" Grape 191 

M of lead 161 



PAGE 

Sulphur , . . . 113 

Sulphuretted hy - | 

drogen ) x 7 

Symbols 19 

Tannin 211 

Tapioca 185 

Tar 205 

Tartar emetic 211 

Tartar, Salts of (sal- I 

soda) J I33 

Tea 215 

Tin 157 

Turpentine 224 

Type-metal 172 

Tyrian purple 217 

Verdigris 159 

Vermilion 170 

Ventilation 79 

Vinegar 198 

Vitriol, Blue 159 



PAGE 

Vitriol, Green 155 

" Oil of 114 

11 White 157 

Water 56 

Water-lime 137 

Wax 221 

11 Sealing 161 

White-lead 161 

Whiting 139 

Wines 195 

Wood, Distillation of. 205 

11 -spirit 201 

11 -vinegar 205 

Wood-tar 205 

Woody fibre 186 

Yeast 193 

Zinc 156 

" Sulphate 157 

41 White 157 



CHEMICAL APPARATUS. 



This Set is adequate for the performance of the 
leading experiments in any text-book. We would call special 
attention to the extremely low price at which it is offered. 



Alcohol. 

Acid, Sulphuric. 

" Nitric. 

11 Hydrochloric. 

1 ' Arsenious. 

" Oxalic. 

1 ■ Tartaric. 
Ammonium Chloride. 
" Nitrate. 

11 Sulphide. 

Ammonia Water. 
Antimony (Metallic). 
Barium Chloride. 

" Nitrate. 
Bone Black. 
Calcium Fluoride. 
" Sulphate. 
Copper Sulphate. 
Carbon Disulphide. 
Ether. 

Ferrous Sulphide. 
" Sulphate. 
Gun Cotton. 
Iodine. 

Lead Acetate. 
Litmus. 
Mercury. 
Magnesium Ribbon. 

" Monoxide. 
Manganese Dioxide. 
Nut Galls. 
Phosphorus. 



PRICE, $15. 



Potassium. 

" Ferrooyanide. 

" Chlorate. 

" Hydrate. 

" Nitrate. 

" Bichromate. 
Strontium Chloride. 

" Nitrate. 
Sulphur. 
Silver Nitrate. 
Sodium (Metallic.) 
" Bi borate. 
" Carbonate. 
" Sulphate. 
Blowpipe. 

Deflagrating Spoon. 
Evaporating Dish. 
Evolution Flask. 
Filters. 
File. 
Funnel. 
Graduate. 
Glass Tubing. 
Lead Dish. 
Nest of Crucibles. 
Retort. 

Rubber Tubing. 
Spirit Lamp. 
Test Tubes. 
Tripod. 
Wedgewood Mortar. 



We would recommend the above to such schools as 
have not the means to purchase the more comprehensive set. 



A NEW AND ENLARGED SET OF 

CHEMICAL APPARATUS. 

Prepared expressly for the performance of the experiments 
in the new edition of Steele's Fourteen Weeks in Chemistry, 



PRICE, $30. 



Acid, Sulphuric. 
44 Nitric. 
" Hydrochloric. 
" Ar«enious. 
" Oxalic. 
" Tartaric. 
Ammonium Chloride. 
44 Nitrate. 

" Sulphide. 

Ammonia Water. 
Antimony. 
Alcohol. 

Barium Chloride. 
14 Nitrate. 
Bone Black. 

Cobalt Nitrate (solution). 
Calcium Fluoride. 
" Sulphate. 
Copper. 

Carbon Disulphide. 
Ferrous Sulphide. 
" Sulphate. 
Gun Cotton. 
Iodine. 
Lead Acetate. 

44 Monoxide. 
Litmus (bept). 
Magnesium Ribbon. 
Manganese Dioxide. 
Mercury. 
Mercuric Chloride. 

44 Oxide. 
Nut Galls (powdered) 
Potassium Ferricyanide. 
•' Iodide. 

u Permanganate. 

" Bichromate. 

Phosphorus 
Potassium (Metallic.) 
44 Chlorate. 



Potassium Hydrate. 

44 Nitrate. 

14 Chromate. 

" Cyanide. 

•' Ferrocyanide 

Sulphuric Ether. 
Sodium (Metallic). 
Biborate. 

" Carbonate. 

" Sulphate. 
Strontium Chloride. 

44 Nitrate. 

Sulphur. 
Silver Nitrate. 
Blowpipe. 
De dci grating Spoon. 
Evaporating Dishes. 
Evolution Flask. 
File (triangular). 
Funnel. 

Filtering Paper. 
Florence Flask. 
Graduate. 

Glass Tubing, assorted. 
Gas Bag with Stop Cock. 
Lead Dish. 
Metric Graduate. 
Nest of Crucibles. 
Pneumatic Trough. 
Retort. 

Retort Stand (3 Rings). 
Rubber Tubing. 
Scales and Weights. 
Spirit Lamp. 
Test Tubes. 
Wedg^wood Mortar. 
"Wire Gauze. 
Wooden Retort Stand, with 

cork shields 



This Set is adequate for the performance of all the 
experiments in any ordinary text book. 



PHILOSOPHICAL APPARATUS. 



This Set is adequate for the performance of the 
leading experiments in any text-book. We would call special 
attention to the extremely low price at which it is offered. 



PRICE, SIOO. 



MECHANICS. 

Centrifugal Hoops. 

Collision Balls. 

Rocking Horse, balanced. 

ELECTRICITY. 

12 In. Plate Machine. 
Spiral Tube. 
Leyden Jar — quart. 
Electric Bells. 
Discharger. 
Plates for Images. 

PNEUMATICS. 

Air Pump and Receiver. 

Globe to Weigh Air. 

Hemispheres. 

Hand and Bladder Glass. 

Fountain in Vacuo. 

HYDROSTATICS. 

Equilibrium. 
Bottle Imps. 
Hydrometer and Jar. 
Siphon. 
Water Hammer 



OPTICS. 

Compound Microscope. 

Magnifier. 

Concave and Convex Mirrors. 

Prism. 

Set Lenses. 

MAGNETISM & GALVANISM. 

Pot Battery. 
Bar Magnet. 
Electro Magnet. 
Magnetic Needle. 
Dip Needle. 

CHEMISTRY. 

Retort Stand. 

Barometer Tube and Mercury. 

Glass Tubes, Assorted. 

Compound Bar. 

Spirit Lamp. 

Rupert's Drops, 6. 

Porous Cup. 

Flask. 

Bulb Tubes, 6. 

Funnel and Filters. 

Glass Tubes for Sound. 



We would recommend the above to such schools as 
have not the means to purchase the more comprehensive set. 



THE HEW AND ENLAE9ED SET OF 

PHILOSOPHICAL APPARATUS. 

Prepared expressly for the performance of the experiments 
in the new edition of Steele's Fourteen Weeks in Physics. 



PRICE, $150. 



PROPERTIES OF MATTER. 

Metre and Yard. 

Porous Cup. 

Inertia Apparatus. 

Collision Balls. 

Collision Plate. 

Gyroscope. 

Cohesion Plates. 

Rupert Drops. 

Capillary Tul'e^. 

Apparatus for diffusion of Gases. 

n u osmose u " 

Apparatus for diffusion of Liquids 

" *• osmose '* *' 

Centre of Gravity. 
Central Forces. 

MECHANICS. 
Pulleys and Weights. 
Lever. 

Weoge (Hinged). 
Screw. 

PNEUMATICS. 
Air Pump. 

Receiver for Air Pump. 
Hand and Bladder Glass. 
Magdeburg Hemispheres. 
Barometer r J ube. 
Guinea and Feather Tube. 

HYDROSTATICS. 

Equilibrium Tubes. 

Hydrometer. 

Jar for Hydrometer. 

Gla«s Lift I 'urn p. 

Glass Force Pump. 

Siphon. 

Bottle Imp. 



ACOUSTICS. 

Diapason. 

Bow. 

Resonant Jar. 

Sonometer. 

G 1 as -» Plates for Chladni Figures. 

Holder for " 4< •' " 

Organ Tube. 

OPTICS. 

Prism. 

Set of Lenses. 

Concave aud Convex Mirrors. 

HEAT. 

Pulse Glass. 

Compound Bar. 

Spirit Lamp. 

Air Thermometer. 

Flask. 

Stand for Flask. 

Glass Tubing. 

ELECTRICITY. 

Battery. French Cell. 
Electro Maguet. 
Gunpowder Cup. 
Needle on Stand. 
Bar Magnet. 
Electrical Machine. 
Leyden Jar. 
Discharger. 
Electrical Chime. 
Flier. 

linage Plates. 
Pair Pith Images. 



This Set is adequate for the performance of all the 
experiments in any ordinary text book. 



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